Evolution and Classification of Mesozoic Mathildoid Gastropods

About 150 Mesozoic (mostly Early and Middle Jurassic) species of the heterobranch superfamily Mathildoidea are classified into four families and 27 genera. Most taxa are assigned to the families Mathildidae, Gordenellidae, and Tofanellidae while the Triassic family Anoptychiidae holds only a single genus and is restricted to the Late Triassic. Mathilda janeti is designated as type species for the genus Promathildia. Earlier designations are invalid because they refer to species which were not originally included in the genus Promathildia. As a consequence, Promathildia is transferred fromMathildidae to Gordenellidae. The generic assignment of numerous mathildoid species is changed. The suggested classification represents an arrangement which is based on shell characters; it is not based on a cladistic phylogenetic analysis.However, a great number of fossil taxa can only be classified based on shell characters. A high mathildoid diversity has been recognized from the Late Triassic Cassian Formation. Many of these taxa are unknown form the Jurassic and probably became extinct during the end-Triassicmass extinction event.However, at least five genera (probably eight) survived the end-Triassicmass extinction event. Tricarilda, Jurilda, and Promathildia are rather conservative, long ranging groups of high Jurassic species diversity. They probably gave rise to the modern Mathildidae. One new genus is described: Angulathilda gen. nov.


Introduction
The present paper reviews and discusses Mesozoic and espe− cially Jurassic genera and families of the heterobranch gas− tropod superfamily Mathildoidea. Mathildoidea form a ma− rine group of basal Heterobranchia. The family Mathildidae is usually included in the superfamily Architectonicoidea but also used as superfamily Mathildoidea (Bandel 1995;Bouchet et al. 2005). The modern Mathildidae are of moder− ate diversity with about 130 nominal species (Bieler 1995). They occur in shallow to deep water and feed on cnidarians (Haszprunar 1985;Healy 1998). There are few studies on the anatomy of this group (Haszprunar 1985) and there are no molecular studies so far. In modern biota, Mathildoidea are relatively rare (Healy 1998). However, Mathildoidea can be common in Mesozoic samples. The undoubted fossil history of Mathildoidea goes back to the Late Triassic (e.g., Kittl 1894;Bandel 1995). The superfamily is especially abundant in Early and Middle Jurassic deposits (e.g., Schröder 1995; acters are useless as pure allegations. However, we admit that the present classification of fossil Mathildoidea represents an arrangement, which is not based on a cladistic phylogenetic analysis. In the absence of a clear phylogenetic framework, the here suggested arrangement is nevertheless justified.
The present work focuses on the type species of Jurassic mathildoid genera. Each genus will be discussed according to its morphological characters and its temporal occurrence. Moreover, we will try to assign the described Jurassic mathil− doid species to the appropriate genera whenever possible.
A large number of Jurassic mathildoid species haven been placed in the genus Promathildia Andreae, 1887. As will be shown below, the traditional designation of the type species of this genus is invalid. A new type species is desig− nated here and this changes the concept of the genus Pro− mathildia considerably.
Family Mathildidae Dall, 1889 Remarks.-The family Mathildidae is based on the modern genus Mathilda that has a Pliocene type species. Numerous Triassic to Recent species and several genera are assigned to this family. However, there is no report from the Palaeozoic. Mathildidae are most diverse in the Jurassic and are repre− sented by a large number of species. The principal morphol− ogy of the group is rather conservative but various character combinations occur. Few characters seem to be suitable to recognize genera so that the systematics of the Mathildidae is difficult. The number of spiral ribs on the whorl face of the early teleoconch, immediately after the protoconch (primary spiral ribs) seems to be a useful character for a classification on the genus−level. In Mathildidae, there are 2, 3, 4 and sometimes more primary spiral ribs. The spiral rib directly at the suture is here not regarded as a primary spiral rib. Gründel (1973) used the number of primary spiral ribs for a subdivision in genera and subgenera: Jurilda (later Pro− mathildia) with two primary spiral ribs, Tricarilda with three primary spiral ribs und Turritelloidea (later Turrithilda re− spectively Mathilda) with four and more primary spiral ribs. Other authors considered this subdivision as artificial (e.g., Bieler 1995;Kaim 2004). Kaim (2004) treated Tricarilda− and Turrithilda−species (3 and more primary spiral ribs) under the genus name Mathilda. However, those with two primary spi− ral ribs were assigned to Promathildia although this character was generally not considered valid by him. Bieler (1995) in− vestigated Recent mathildids and concluded that it is unclear whether the character complex of spiral rib pattern is suitable to recognize monophyletic genera and that anatomical studies (and one may now also say molecular studies) are needed to test whether this pattern give a phylogenetic signal. These doubts may be justified but the need for a subdivision of the large number of fossil mathildids remains. For Jurassic mathildids the number of primary spiral ribs seems a readily available character which in combination with other charac− ters facilitates a subdivision in genera. However, we are aware that this procedure is artificial to some degree. This problem is typical for highly diverse fossil groups which have notoriously conservative shell morphology.
Additional characters which may be used for a taxonomic subdivision are shell shape (e.g., unusually broad and strongly keeled shells) and the presence of a micro−ornament consist− ing of numerous fine spiral ribs. This micro−ornament seems not to be strictly diagnostic on the genus level; it is for instance weakly developed in some species of Jurilda and Tricarilda but is characteristic for the genera Carinathilda, Angulathilda, and Erratothilda.
As outlined below, the diagnosis of Promathildia is changed because of the new designation of a type species. For those Jurassic mathildids with two primary spiral ribs (Promathildia sensu Gründel 1997 andKaim 2004), the name Jurilda Gründel, 1973is available. Tricarilda Grün− del, 1973 can be used for species with three primary spiral ribs. Mathilda Semper, 1865 (with modern type species) is used for species with four and more primary spiral ribs.
Remarks.-We include Jurassic species with four or more pri− mary spiral ribs in Mathilda with the exception of Errato− thilda−species which have a broad shell and strongly keeled whorls. Moreover, most Erratothilda species have a coaxial protoconch and a distinct micro−ornament and differ from Mathilda in these respects. We leave the question whether the Jurassic species which have been assigned to Mathilda are re− ally congeneric with the Pliocene type species open although we consider it unlikely. Gründel (1976) re−described the type species Mathilda quadricarinata and reported the presence of four primary spiral ribs. In contrast, Bandel (1995: 39) men− tioned in his key to Triassic Mathildoidea that Mathilda is characterized by two primary spiral ribs. However, he obvi− ously did not refer to the type species. Most of the modern spe− cies assigned Mathilda by Bieler (1995) have four or more pri− mary spiral ribs; however, some have only three. Walther (1951) introduced the generic name Turritelloidea for species which are here assigned to Mathilda. Schröder (1995) replaced Turritelloidea by Turrithilda because he as− sumed that the ending "−oidea" can only be used in names of superfamilies-this replacement is of course invalid. The type species of Turritelloidea (Turritella opalina Quenstedt, 1852) is a representative of the Gordenellidae and differs consider− ably from Jurassic Mathilda−species (Gründel 2005b).
Stratigraphic and geographic range.-The earliest Mathilda is known from the Toarcian; similar species have been re− ported from the Late Cretaceous (e.g., Mathilda hexalira Dockery, 1993); Germany, Poland, Russia, ?USA, Ukraine.
Stratigraphic and geographic range.-Possible Triassic rep− resentatives of Jurilda are still doubtful and may belong to the genus Teretrina Cossmann, 1912 (AN and JG personal obser− vations). The type species, Turritella bolina Münster, 1841, which are distinctly opisthocyrt between the adapical suture and the abapical spiral rib, i.e., their cenit is situated above the abapical primary spiral rib. However, other species which have been described as Promathildia species by Bandel (1995) have a course of the growth lines including axial orna− ments similar to that of the Jurassic species. The first certain members of Jurilda are of Hettangian age. For instance Chapuis and Dewalque (1854), Terquem and Piette (1868), and Piette (1855) reported species which according to their de− scriptions and illustrations should be classified to Jurilda. Jurilda is at least present until the Early Cretaceous (Schröder 1995;Kaim 2004). The last occurrence of the genus is unclear. The genus is known from Germany, Poland, Italy, Ukraine.
Remarks.-In its present composition, Gymnothilda is rather heterogeneous. However, only a few species are included so that a subdivision is not warranted. Gymnothilda contains species with one or two primary spiral ribs and with or with− out micro−ornament. Kaim (2004) restricts the genus to Early Cretaceous species (Valanginian). The oldest species as− signed to Gymnothilda is the Bathonian G. dispiralis Grün− del, 1997 (late Bathonian to early Callovian). However, Kaim (2004: 134) doubted this generic assignment and stated that it probably represents a species of Promathildia, and that its reduced axial ornamentation derived independently. We consider this as a possible interpretation but leave the Middle Jurassic G. dispiralis in Gymnothilda until we know more about this genus. Stratigraphic and geographic range.-Gymnothilda as un− derstood here, has its first occurrence in the late Bathonian and ranges with G. torallolensis Kiel and Bandel, 2001 into the Late Cretaceous (Campanian). Gymnothilda pagodoidea Kiel, 2006 (Albian) belongs to Bathraspira (see below). It is also possible that the only known specimen of G. torallolensis rep− resents a juvenile of Bathraspira. The genus is known from Germany, Poland.
Remarks.-Usually, Bathraspira was assigned to the caeno− gastropod familiy Procerithiidae (for example Cossmann 1906;Abbass 1973;Kiel 2006). Protoconch and early teleo− conch whorls have been unknown until Kiel (2006) described Gymnothilda pagodoidea from the Albian of Madagascar. This species unites a mature teleoconch which is typical for Bathraspira and a protoconch as well as early teleoconch whorls which are typical for Gymnothilda. If the juvenile specimen of this species illustrated by Kiel (2006: fig. 8/1) was found alone, it would be certainly assigned to Gymnothilda. Steffen Kiel (personal communication 2010) also agreed that "Gymnothilda" pagodoidea belongs to Bathraspira. It is yet unknown whether this ontogenetic change is also present in other Bathraspira species. In any case, Bathraspira pagodo− idea (Kiel, 2006)  Emended diagnosis.-Protoconch (always?) coaxial; shell moderately broad with two primary spiral ribs and keeled whorls; whorl outline oblique and straight between keel and abapical suture, weakly convex above the keel; base strongly and evenly convex without demarcation to whorl face; weaker secondary spiral ribs and reinforced growth lines form a fine reticulate pattern; a distinct micro−ornament of numerous fine spiral threads is present.
Remarks.-Differences to Angulathilda are discussed below. Jurilda has a more slender teleoconch and the keel is less pro− nounced. Moreover, Jurilda lacks a distinct micro−ornament.  fig. 113A 1 ). B, C. Bathraspira pagodoidea (Kiel, 2006), Mahajanga Basin/Madagascar, Albian; from Kiel (2006: figs. 8.1, 8.2). Ju− venile (B) and adult (C) specimens. Diagnosis.-Protoconch medio− to coaxial, smooth or with ra− dial wrinkles; shell moderately broad with two primary spiral ribs and strongly keeled whorl face; whorl face somewhat concave below and above keel; numerous fine axial ribs (or strong growth lines); base slightly to moderately convex; whorls face joins base at distinct angulation with strong spiral rib; micro−ornament of numerous fine spiral threads present.
Remarks.-Mathilda binaria Hébert and Eudes−Deslong− champs, 1860 sensu Andreae (1887) and Carinathilda pro− cera Gründel, 2006 do not show any micro−ornament (in the latter, this could be due to preservation) and are therefore placed only tentatively in Angulathilda. The Cretaceous Carinathilda parviruga Kiel, 2006 has a distinct umbilicus which is not present in other species of this genus. Several spe− cies which were described before SEM studies were possible cannot neither be included nor excluded with certainty be− cause the diagnostic relevant presence of a micro−ornament was not tested. In contrast to Angulathilda, Carinathilda has a strongly convex base which is not demarcated from the whorl face by an edge; moreover the whorl face is slightly convex below the keel in Carinathilda. Erratothilda has three or more pri− mary spiral ribs. Emended diagnosis.-Shell and ornament basically as in Angulathilda. However, Erratothilda has three or more pri− mary spiral ribs. Erratothilda has a pronounced micro−orna− ment.
Remarks.-The characteristic micro−ornament has not been shown for Erratothilda wascherae Gründel, 2006 which co− mes from a locality at which the preservation is not sufficient to show such fine details.
Family Gordenellidae Gründel, 2000 Remarks.-In our opinion, the diagnostic differences be− tween Mathildidae and Gordenellidae as outlined by Gründel (2000) remain valid despite Guzhov's (2007) doubts. Gorde− nellids differ from mathildids in the rather large size, slender to very slender shape, high number of whorls, early teleo− conch whorls with mathildid ornament (three primary spiral ribs, middle and abapical spiral strongest and angulating whorl profile, numerous opisthocyrt axial ribs), and change of the ornament on mature teleoconch whorls (sometimes complete reduction) (see below).
Included species: There are certainly more than the here listed species, which belong to the genus Promathildia. However, descriptions and il− lustrations are commonly insufficient for a reasonable assignment. For the majority of the species listed below, the protoconch is unknown so that the placement of these species is also somewhat uncertain (the transaxial, strongly emerging protoconch is diagnostic  (1869): "This suggests that the spelling Promathildia is not an original incorrect spelling but that Andreae volun− tarily used the emendation Mathildia combined with the prefix Pro−." Emended diagnosis.-Shell slender, relatively large, with many whorls; protoconch heterostrophic, transaxial, dis− tinctly emerged, detached or almost detached from initial teleoconch whorl; teleoconch whorls with 3 (4) primary spi− ral ribs, convex with distinctly deepened suture, angulated at two of the primary spiral ribs (octagonal whorl outline) or with one of the primary spiral ribs as keel. Numerous fine ax− ial ribs or strong growth lines; teleoconch ornament does not change during ontogeny or changes are only minor.
Remarks.-Promathildia is now included in Gordenellidae because Mathilda janeti is here designated as type species of this genus and this species is a gordenellid. Andreae (1887)  eminently in size. As far as I can overview the Jurassic mathildids, they seem split into at least 2 morpho−groups. The more slender ones with pronounced reticulate ornament group around Mathildia Janeti Coss., M. reticularis Piette etc. by almost lacking a siphonal outlet of the aperture. In the others, the spiral keels exceed the fine transverse ribs by far and its type is formed by M. binaria. These are broader and have a rather wide but flat anterior outlet of the aperture. Ac− cording to this aperture shape, they resemble Messalia and Mesostoma. The latter Tertiary genus has also the same orna− ment. I am retaining these forms in Mathildia because I found one of the most important characters, the inverse em− bryonic end, in a good specimen from the Pfirt. Species re− lated to M. binaria have commonly been assigned to Alaria as is the case in the previously mentioned species Alaria clathrata Terq. & Jourd. and Pterocera Cassiope d'Orbigny from the Oxfordian of Neuvizy, which was assigned to Alaria by Piette". This citation shows that Promathildia was originally meant as a kind of chronotaxon encompassing the Jurassic mathildids which are allegedly larger than living members of Mathilda (size is the only diagnostic feature mentioned by Andreae 1887). It is clear that Andreae (1887) did not designate a type species for Promathildia and did not provide a sufficient diagnosis. He distinguished two mor− pho−groups within Promathildia but this is irrelevant for no− menclature because he did not name these groups. The desig− nation of M. binaria as "type" for one of the unnamed subdi− visions of Promathildia does not represent the designation of a type species because it relates not to a name bearing group. This is also true for Koken's (1889: 458-459) treatment of Promathildia. This author repeated Andreae's (1887) text verbally and as Andreae (1887), he did not name any of the two proposed subgroups of Promathildia. Andreae (1887) (1889) used the genus Promathildia for Triassic mathildoids including for "Cerithium bisertum" from the Cas− sian Formation. Kittl (1894) was the first to formally assign species (from the Triassic Cassian Formation) to the genus Promathildia in binominal form (Nützel and Erwin 2004). Cossmann (1912) designated Cerithium bisertum Münster, 1841 from the Late Triassic Cassian Formation as type species of Promathildia. However, this designation is invalid because Cerithium bisertum has not been originally included by Andreae (1887) (ICZN article 67.6, 69.1, 69.2.2). Moreover, this species differs significantly from the Jurassic species that were mentioned by Andreae (1887) as examples for Pro− mathildia. Thus this designation is in conflict with Andreae's (1887) intention. In the following, we will discuss each of the originally included species as possible type species for Pro− mathildia: -Mathilda janeti Cossmann, 1885 (Fig. 4A-C) represents probably a species of the genus Clathrobaculus Coss− mann, 1912 according to its overall morphology. Coss− mann (1885: pl. 14: 20, 21) reported a heterostrophic protoconch of the Mathilda−type for M. janeti (see Fig. 4A herein); therefore this species is certainly a mathildoid. Obviously, Cossmann (1885) had only juvenile specimens at hand. The heterostrophic, transaxial protoconch and the slender shell of M. janeti would support an assignment to Clathrobaculus. -Mathilda reticularis (Piette, 1855) (Fig. 4D, E) was insuffi− ciently described by Piette (1855) and no illustration was given. It was described and illustrated by Cossmann (1885) (1843: pl. 11: 8, 9). Whole specimen (A 1 ), last whorl enlarged (A 2 ). B. Promathildia sp., cf. eucycla (Hébert and Eudes−Deslongchamps, 1860), erratic boulder from Vorpommern (NE Germany), Callovian; from Gründel (2000: pl. 1: 2). C. Promathildia sp., bore Usedom 3/63 (NE Germany), Late Bathonian, protoconch; from Gründel (1997: pl. 4: 48). D. Falsoebala compacta Gründel, 1998, bore Kłęby (formerly Klemmen) 1/37, Poland, Callovian, protoconch.
Mathilda reticularis. It is a teleoconch fragment which is 13.6 mm high. The whorl face is ornamented with four spi− ral ribs, two of which are more pronounced on the earliest preserved whorls. Protoconch, primary spirals on the early teleoconch, and aperture are unknown. Due to this incom− plete preservation, it is not suitable as type species of Promathildia.
-Alaria clathrata Terquem and Jourdy, 1871 (Bathonian; Fig. 1E) and Turritella binaria Hébert and Eudes−Deslong− champs, 1860 (Callovian; Fig. 1F) closely resemble each other and both species are congeneric (see above). Both were repeatedly assigned to the genus Teretrina Cossmann, 1912. Teretrina has a Triassic type species which differs significantly from both Jurassic species (AN and JG own observations) so that this generic assignment can be refuted. Alaria clathrata and Turritella binaria occupy a certain place within the Jurassic Mathildoidea (see below). The teleoconch of both species is relatively well known. How− ever, protoconch and early teleoconch including primary spiral ribs have not been described or illustrated to this point.  (1887) identified some of his Oxfordian speci− mens as Mathilda binaria (Hébert and Eudes−Deslong− champs, 1860), a species which was originally described from the Callovian of France. However, this is certainly a misidentification-there are strong differences in shape and ornament. For instance, Andreae's (1887: pl. 1C: 1-3) illus− trations show a hardly convex base bordered by a strong spi− ral rib so that the basal edge is angular. It probably represents an undescribed species of the genus Angulathilda. A descrip− tion of a new species is not warranted yet because of the in− sufficient knowledge of this species. It is very likely that it represents a mathildid because Andreae (1887: 24) men− tioned that the protoconch is heterostrophic.
In conclusion, of all species which were mentioned by Andreae (1887) when introducing the genus Promathildia, only Mathilda janeti is sufficiently known to characterize the genus. Therefore, we designate Mathilda janeti Cossmann, 1885 as a type species of Promathildia Andreae (1887). This species is most probably congeneric with the type species of the genus Clathrobaculus Cossmann, 1912 (Fig. 5A) and therefore Clathrobaculus is a junior synonym of Promathil− dia. Promathildia janeti is slender, with numerous convex whorls separated by deep suture and has an ornament of two strong spiral ribs; the protoconch is relatively large and trans− axial. These characters are also typical of Clathrobaculus (Cossmann 1912;Guzhov 2007). The relatively small size of the originals of Mathilda janeti as illustrated by Cossmann (1885) probably indicates that he had only juveniles at hand. Our designation of a type species from those species which were originally included by Andreae (1887) changes the pre− vious concept (e.g., Bandel 1995;Gründel 1997;Kaim 2004) and the genus should now be included in the family Gor− denellidae Gründel, 2000 (see discussion of the Gordenellidae below); this group had its greatest diversity in the Jurassic.
The protoconch is known for the following species of Promathildia: Mathilda janeti Cossmann, 1885 (Bathonian), Tricarilda plana Gründel, 1973 with aberrant protoconch sensu Gründel 1997 (Callovian), Clathrobaculus sp. 3 sensu Kaim (2004) (Bathonian), and Clathrobaculus demissus Gründel, 2006 (Bathonian). All other species listed above have a teleoconch morphology which agrees with the diag− nosis of Promathildia as given above. Haas (1953) described several species from the Late Trias− sic and the transition to the Early Jurassic of Peru which closely resemble Promathildia. He assigned some of them to Clathrobaculus (see also Guzhov 2007), e.g., Promathildia (Teretrina) bolinoides Haas, 1953, Promathildia (Teretrina) aculeata Haas, 1953, and Promathildia (Clathrobaculus) su− bulata Haas, 1953. For some of these species Haas (1953) could report a heterostrophic protoconch. However, these protoconchs cannot be evaluated from the illustrations pro− vided by Haas (1953). According to their teleoconch morphol− ogy, it is very likely that these species belong to Promathildia or are closely related to this genus. Promathildia seems to be absent in the Late Triassic Cassian Formation; none of the spe− cies reported by Bandel (1995) seems to represent this genus.
Gordenella Gründel, 1990 differs from Promathildia in having straight to concave sides of mature teleoconch whorls. Moreover, in Gordenella the middle primary spiral is moving toward the abapical suture during ontogeny; at the same time, the primary spiral rib becomes weaker (in some cases it fades completely). Gordenella also differs in showing an onto− genetic weakening of the axial ribs. Stratigraphic and geographic range.-The stratigraphic oc− currence of Promathildia can only be given preliminarily, because many species which probably belong to this genus are insufficiently known. The oldest certain species is of Hettangian age (Cerithium collenoti Martin, 1862 Guzhov (2007), Turritella sauvagei Buvignier, 1852, Turritella divisa Ilovaisky, 1904, Turritella complanata Brösamlen, 1909, and Promathildia bigoti Cossmann, 1913 are syn− onyms of Turritella fahrenkohli; Turritella bicostata Ilovaisky, 1904 and probably also Turritella praecursor Andreae, 1887 are synonyms of Gordenella krantzi.
Emended diagnosis.-Shell slender, large, with many whorls; protoconch heterostrophic, transaxial, distinctly emerged, de− tached or almost detached from initial teleoconch whorl; early teleoconch whorls with two strong and often several weaker spiral ribs as well as numerous opisthocyrt axial ribs; strong abapical spiral rib moves down towards the abapical suture until it is positioned slightly above the abapical suture; this spi− ral becomes stronger during ontogeny; at the same time, strong adapical spiral is weakening and may fade entirely; be− low adapical suture one or two spiral ribs become increasingly stronger; whorl face straight to concave (the latter in most spe− cies); axial ribs are reduced to strong growth lines on the last whorls of adult specimens.
Remarks.-The name Clathrobaculus, as cited in older litera− ture, is replaced in the following discussion with Promathildia according to its new definition. Guzhov (2007) described the characteristic type of protoconch for several species represent− ing Gordenella. The same type is also present in Promathildia. When Gründel (2000) introduced the family Gordenellidae, he considered Clathrobaculus as being closely related to Gor− denella Gründel, 1990. However, he decided that the separa− tion line between Mathildidae and Gordenellidae runs be− tween both genera because Clathrobaculus lacks an important character of the Gordenellidae, namely the conspicuous onto− genetic change of the teleoconch sculpture which can even re− sult in a complete reduction of the ornament in mature teleo− conch whorls. Clathrobaculus and Gordenella share the rela− tively large size (for mathildoids), the very slender multi− whorled shell and especially the transaxial protoconch which is widely elevated and not covered by the initial teleoconch whorl. Therefore, Clathrobaculus (= Promathildia) is as− signed to Gordenellidae. All genera of the Gordenellidae have an early ontogenetic "Clathrobaculus"−stage, which has also been identified by Guzhov (2007). Guzhov (2007) assumed a fluent transition from Clathro− baculus sensu stricto in his sense (= Promathildia herein) and species of Gordenella sensu Gründel (2000). Therefore, he considered Gordenella to represent a synonym of Cla− throbaculus. Clathrobaculus medidilatatus Guzhov, 2007 has a relatively weak ontogenetic change of the teleoconch ornament i.e., rounded whorl flanks, minor displacement of the strongest spiral rib in an abapical direction, weakening of  (Schmidt, 1905), Kłęby (formerly Klemmen), Poland, late Oxfordian. A. From Gründel (2000: pl. 1: 8). B. From Gründel (2000: pl. 1: 11). C. Turritelloidea opalina (Quenstedt, 1852), Mistelgau, Germany, late Toarcian, see also Gründel (2005: figs. 2/1, 3). D. New genus, new species to be described elsewhere, Buttenheim, Germany, late Pliensbachian; whole specimen (D 1 ), early whorls (D 2 ). the axial ornament associated with an increase in the number of axial ribs per whorl. Even if this species is included in the genus Clathrobaculus, there are still pronounced differences between Clathrobaculus sensu stricto = group 1 according to Guzhov (2007) and groups 2+3 as defined by Guzhov (2007) (= Gordenella sensu Gründel 2000): (i) Clathrobaculus has convex and keeled/angulated teleoconch whorls and its teleoconch ornament does not change during ontogeny (or only minor changes occur); (ii) groups 2+3 as defined by Guzhov (= Gordenella sensu Gründel 2000) has mostly a concave whorl face (or it is straight) and a pronounced ontogenetic change of the teleoconch ornament which was described in detail by Gründel (2000). The morphological differences between groups 1 and 2+3 sensu Guzhov are much more pronounced than the differences between groups 2 and 3 (subgenera of Gordenella?). Therefore we consider Gordenella to represent a valid genus, separate from Cla− throbaculus (= Promathildia).
Stratigraphic and geographic range.-Certain Gordenella− species with known protoconch and first teleoconch whorls including an early Promathildia−like stage are known from the Callovian and Oxfordian. Specimens with typical Gor− denella−like mature teleoconch whorls were reported from the Bathonian by Gründel (2000) and from the Bajocian by Eudes−Deslongchamps (1866). It is very likely that this ma− terial represents Gordenella. The generic assignment of Gor− denella? sp. from the Late Pliensbachian as reported by Schubert et al. (2008) remains doubtful. Procerithium (Cos− mocerithium) kunceviciense Gerasimov, 1992 is also insuffi− ciently known. Thus, Gordenella ranges from the Bajocian to the Oxfordian according to the current state of knowledge. The genus is known from Germany, France, Luxembourg, Poland, Russia.
Genus Turritelloidea Walther, 1951(= Turrithilda Schröder, 1995= ?Costacolpus Marwick, 1966) (Bistram, 1903)? sensu Gründel 2003b, Het− tangian; ?Turritelloidea sp. sensu Schubert et al. 2008, Pliensbachian. Diagnosis.-Shell median−sized to large and highly conical. The heterostrophic protoconch of the Mathilda−type is nearly coaxial. On the first teleoconch whorl two strong keel−like spi− ral ribs and numerous axial ribs are developed. The last whorls have 6-7 spiral ribs of almost the same strength. In this part of the shell, the ribs are very broad (broader than the spiral fur− rows between them). The axial ribs become also broader and at the same time weaker. The ornament of the last whorls of adults consists only of broad spiral ribs (the base included).
Remarks.-The protoconch is only known for the type spe− cies. Hudleston (1892: 230) made the following remark for T.? abbas: "Indications of a sinistral apex have been ob− served on one specimen". However, T.? abbas lacks the broadened, band−like spiral ribs and therefore is placed in Turritelloidea only tentatively (see also . The protoconch and the early teleoconch whorls of most of the species listed above are unknown and therefore, the ge− neric assignment of these species is not beyond doubt. These species are placed in Turritelloidea because their mature teleoconch resembles that of the type species. The proto− conch is also unknown for the type species of the genus Costacolpus Marwick, 1966(Turritella solitaria Wilckens, 1922. Its early teleoconch whorls have an ornament of axial and spiral ribs whereas the mature whorls have exclusively spiral ribs. The spiral ribs become very broad and are separated from each other by narrow furrows. The base has sometimes varix−like thickenings. Costacolpus solitaria closely resembles Turritelloidea opalina in general shape and ornament. Thus, it seems to be likely that Costa− colpus represents a junior synonym of Turritelloidea.
In Fig. 6D a yet undescribed genus close to Turritelloidea is illustrated. It is from the Late Pliensbachian of Germany and will be described in the near future in the frame of a larger monograph. Because this genus is important for this work, we give a preliminary description herein. The shell is high−spired with numerous whorls. The early teleoconch whorls are ornamented with few, widely spaced, strong axial ribs. The earliest preserved teleoconch whorls show two me− dian spiral ribs which somewhat angulate the whorl profile. In addition a weaker subsutural spiral is present. The inter− sections of axial and spiral ribs are nodular in early whorls. The position of the primary spiral ribs remains approxi− mately stable during ontogeny. The spiral and axial ribs be− come weaker during ontogeny and intersections are not nod− ular any longer. Numerous additional spiral striae are added on mature teleoconch whorls and axial ornament consists of numerous densely spaced strengthened growth lines. The base is flat and is ornamented with narrow spiral ribs and broader furrows. The protoconch is unknown.
This yet undescribed new genus resembles Turritelloi− dea. However, Turritelloidea has broad spiral ribs separated by narrow furrows on mature teleoconch whorls. The type species of Gordenella (Fig. 6A, B) has a straight whorl pro− file; its mature teleoconch whorls does not show numerous spiral striae. The relatively large size, the high number of whorls and the suppression of axial ribs during ontogeny suggest that the new genus belongs to Gordenellidae.
Stratigraphic and geographic range.-Turritelloidea is cer− tainly as old as Late Toarcian. It is likely that the genus ranges from the Hettangian to the Bajocian and even to the Late Ju− rassic or to the Late Cretaceous (e.g., T. minuta from the latest Jurassic and Costatrochus solitaria from the Late Cretaceous). Diagnosis.-"The small shell has a high spire with numerous flat−sided whorls and distinct suture. The protoconch is coiled sinistral and inclined with respect to the axis of the teleoconch. The first whorls (c. 5) of the juvenile teleoconch are covered with axial and spiral costae, of which the spiral ones are domi− nant. Later whorls are smooth or have indistinct spiral threads up to the edge of the base, while the base is covered by spiral carinae. The umbilicus is narrow and may form the opening to a hollow columella" (Bandel 1995: 18).
Remarks.-Camponella and Proacirsa share important char− acters: Protoconch morphology, ornament of the early teleo− conch as well as reduction of this ornament during ontogeny, and broad spiral ribs on the base. Camponella differs from Proacirsa in being much smaller, in having fewer whorls and in having an umbilicus. Camponella is probably ancestral to Proacirsa. Emended diagnosis.-The protoconch consists of about 1.5 whorls, is heterostrophic and almost coaxial. The early teleo− conch has two or three spiral ribs; the adapical rib is dis− tinctly weaker than the abapical spiral ribs. The spiral ribs are intersected by numerous axial ribs; the intersections are more or less nodular. After a few teleoconch whorls, the ornament fades. Only in some cases, remains of a spiral ornament are present on the last whorls. The base is moderately convex and is ornamented with broad spiral ribs.
Remarks.-The protoconch of a species belonging to Pro− acirsa was described by Gründel (2005b mented with several spiral ribs on the abapical whorl portion which are intersected by numerous axial ribs; intersections of axial and spiral ribs nodular; axial ribs reduced after a few whorls; mature teleoconch whorls with numerous weak spi− ral ribs which are somewhat more distinct in the abapical portion of the whorls; base with numerous somewhat broad− ened spiral ribs.
Remarks.-Proacirsa differs in having three spiral ribs which are distributed over the entire whorl face and in having fewer axial ribs in the early teleoconch whorls, in having rather broad spiral ribs on the base and a smooth whorl face in mature teleoconch whorls.
Family Tofanellidae Bandel, 1995 Remarks.-The Tofanellidae are characterized by coaxial protoconchs with a morphology that is considered to be diag− nostic for the family (Bandel 2005: 19): "Its embryonic whorl is left coiled and immersed in the apex of the larval shell. The rounded whorls of the larval shell gradually change from left coiling to plane coiling and finally to dextral coiling." However, even some Mathildidae have coaxial protoconchs (e.g., Erratothilda). It seems that the differentia− tion between Mathildidae and Tofanellidae is unclear in such cases. For instance, why is the protoconch of Mathilda bolina von Münster, 1841 sensu Bandel (1995: pl. 2: 2) of the mathildid type whereas that in pl. 11: 8 (Tofanella cancellata Bandel, 1995) allegedly tofanellid (see Fig. 8A, B)? And is Tricarilda octoangulata Gründel, 2006 then really a species of the Mathildidae or does it belong to Tofanella? Obviously these cases need further clarification. The representatives of the Tofanellidae are generally small and have been overlooked in many studies. It seems to be likely that only a small part of the gone species diversity and distribution have been assessed. So far, the family has not been reported from the Late Cretaceous and Cenozoic. However, Bandel (2005) reported Recent representatives of the family. At least some tofanellid genera seem to be long ranging al− though all range dates most be treated with caution. Gründel (1998) subdivided the family Tofanellidae into the two sub− families Tofanellinae Bandel, 1995and Usedomellinae Grün− del, 1998. Kaim (2004 refuted this subdivision and even Bandel (2005: 19) was sceptical: " Gründel (1998) suggested to split the taxon into the subfamilies Tofanellinae and Use− domellinae, but the genera held herein contain species which are sometimes very difficult to place in one genus or the other or to a representative of one subfamily or the other. These subfamilies may, therefore, not be very useful." Despite this statement, Bandel (2005) continued to use both taxa in his pa− per. However, it is indeed difficult to apply Gründel's (1998) concept in some cases (e.g., Camponaxis). Therefore we are reluctant to propose a subdivision of Tofanellidae into sub− families and further studies of more fossil representatives are needed.
Genus Tofanella Bandel, 1995  Diagnosis.-"The turriculate shell has a major keel on the first whorls of the teleoconch, which disappears on later whorls as they become almost flat. The spiral sculpture is crossed by few collabral elements. The protoconch has a smooth surface, and the embryonic shell is immersed in its apex. In the larval whorls the sinistral coiling changes into dextral coiling before onset of the teleoconch. With transi− tion from larval to adult shell sculpture and whorl shape change drastically" (Bandel 1995: 21).
Remarks. -Kaim (2004) considered Urlocella to represent a synonym of Chrysallida Carpenter, 1856. However, Bandel (2005) did not accept this because Chrysallida has no tofa− nellid protoconch and therefore represent a genus of the Pyramidellidae. Instead Bandel (2005) considered Urlocella to represent a synonym of Graphis. We consider this synon− ymy to be unlikely as was outlined above (see Remarks un− der Graphis). Emended diagnosis.-Shell conical; protoconch tofanellid, comprising about two whorls; first teleoconch whorl broader than protoconch; whorls broad in relation to height; suture shallow; whorls smooth except straight growth lines; base convex, not demarcated from whorl face; base indistinctly umbilicated; aperture broadly oval.  Diagnosis.-Shell broadly conical with distinct suture and a tofanellid protoconch. The last whorl is higher than the spire; whorls smooth; growth lines strongly parasigmoidal; base with a distinct umbilicus; umbilicus surmounted by edge; ap− erture broadly oval (after Gründel 2007: 90).

Discussion
The evolution of the Mathildidae in the Jurassic.-Nu− merous species of the Jurassic Mathildidae are insufficiently known and commonly protoconch and early teleoconch are unknown. Micro−ornaments can only be studied with a SEM and therefore, they have only been depicted in some recent studies. Modern studies were almost exclusively conducted on Early and Middle Jurassic faunas from clay and sandstone rocks of central and western Europe deposited in moderately deep water. There are, however, almost no recent studies on mathildoids from calcareous shallow water deposits which were dominant during the Late Jurassic. Even studies about Mesozoic mathildoids from other regions of the world are rare. As outlined above, the status of taxonomically relevant characters is insufficiently known. For these reasons, the stratigraphic ranges (originations and extinctions) of the gen− era discussed here, must be treated with caution and certainly must be continuously updated. Bandel (1995) showed that Mathildoidea were richly diver− sified in the Late Triassic. There was a considerable diversity decline at the Triassic-Jurassic boundary but the Jurilda−group survived. However, it should be kept in mind that most of the Triassic diversity has been reported from tropical intra−plat− form basins partly with transported shallow water material   Gründel, 1999, Grimmen, Germany, late Plien− sbachian. Whole specimen (A 1 ) from Gründel (1999: pl. 8: 8); protoconch in apical view (A 2 ) from Gründel (1999: pl. 9: 2). B, C. Reinbergia inflata Gründel, 2007, borehole Kb Rnb Gm 4/66 Reinberg, Germany, late Pliens− bachian. B. From Gründel (2007: pl. 7: 6, 7). C. From Gründel (2007: pl. 7: 8).
(Cassian Formation). In contrast most of the Jurassic data come from offshore soft bottoms of Central Europe with a more tem− perate climate. Both occurrences differ considerably in facies and depositional environment. Therefore, evolutionary consid− erations based on the composition of these Mesozoic mathil− doid faunas (including Gordenellidae and Tofanellidae) must take into account facies differences as well as their different age. Mathildoid faunas from other parts of the world are poorly known or completely unknown. Therefore, the impact of the end−Triassic extinction is certainly biased. Gründel (1997: 153, table 2) gave an overview over the evolution of the Mathildidae from the Triassic to the Recent. The present study on Jurassic Mathildidae corroborates and improves these results. Kaim (2004: 168, fig. 138) constructed a stratophenetic phylogenetic tree of Mathildoidea, which is on the species− level at least for Jurassic representatives. In this tree, Mathildi− dae are descendants of the Late Paleozoic Donaldinidae. Tri− carilda is considered to represent a synonym of Mathilda. This tree also shows Promathildia (= Jurilda herein) and Mathilda as being present as early as Triassic. Carinathilda and Gymnothilda are descendants of Promathildia. Errato− thilda (adelphotaxon of Carinathilda) together with Tuba Lea, 1833 (not yet found in the Jurassic) represents a lineage of equal rank to the group previously outlined. However, accord− ing to Kaim (2004) it is also possible that Carinathilda and Erratothilda are congeneric.
After an apparent considerable decline of Mathildoidea at the Triassic/Jurassic−transition, the Jurilda−group radiated in the Early and early Middle Jurassic. Numerous species with generally rather conservative morphology evolved. Since the Bathonian new genera occur indicating an increasing mor− phological disparity. Gründel (1997) also discussed the pos− sible relationships of genera within the group.
Tangarilda differs from other Jurassic Mathildidae in hav− ing opisthocyrt growth lines with the backmost point between adapical and middle spiral rib. The genus seems to stand somewhat isolated in the family in this respect. The phylogen− etic meaning of this character is not yet clear. In fact, such growth lines are not present in Mathildidae after the Hettan− gian (Sinemurian?) although numerous well−preserved math− ildids are known from the post−Hettangian Jurassic.
It seems possible that there are closely related Late Trias− sic taxa with similar growth lines (AN personal observation) and that these taxa represent an old evolutionary line which became extinct in the late Early Jurassic.
According to the current state of knowledge, the first cer− tain occurrence of Jurilda is of Hettangian age. Bandel (1995) reported very similar "Promathildia"−species from the Late Triassic Cassian Formation e.g., Promathildia decorata (Klip− stein, 1843). However, the phylogenetic relationships of the diverse Mathildoidea from the Cassian Formation to Jurassic and younger forms are far from being clear (AN and JG un− published data). It is for instance unclear, whether Triassic species with two primary spiral ribs can be assigned to the ge− nus Jurilda. At least in some of these Triassic species, the growth line pattern differs from that of typical Jurilda species and resembles that of the genus Tangarilda. Other late Trias− sic species, e. g., Promathildia sculpta (Kittl, 1894) sensu Bandel (1995), have numerous weak spiral ribs and this pat− tern resembles the micro−ornament of some Jurassic species but is distinctly coarser.
At present, it can be stated that either Jurilda itself or closely related forms were present as early as Late Triassic. This represents a continuous evolutionary lineage which crosses the critical Triassic-Jurassic boundary. This Jurilda lineage continues at until the Early Cretaceous and comprises species with a rather conservative morphology. The younger history of this group is unknown. None of the Recent species described by Bieler (1995) belongs to the Jurilda−group.
Gymnothilda can be derived from Jurilda by a reduction of the ornament. The oldest known species is Gymnothilda dispiralis from the Bathonian. This species has two primary spiral ribs. Forms with a single primary spiral rib are known from the Early Cretaceous. There are also Cretaceous species with two primary spiral ribs. Possibly a reduction of primary spiral ribs occurred within this genus. Gymnothilda tomaszina from the Valanginian has a micro−ornament which resembles that of Carinathilda. Gymnothilda−species have been reported only from a few stages (Bathonian, Valanginian, Campanian) and some are only known from juvenile specimens. Therefore, the evolution of this genus is still largely unknown.
The genus Bathraspira is only known from the Creta− ceous. Protoconch and early ontogeny have been unknown until recently and the genus was assigned to the Procerithiidae or Cerithiidae. Kiel (2006) described a species with proto− conch and early teleoconch whorls (Gymnothilda pagodoi− dea); this species combines a mature teleoconch typical for Bathraspira and an early stage typical for Gymnothilda with a single primary spiral rib. At least this species can be inter− preted as a descendant of Gymnothilda. However, it is unclear whether this is true for other or all species of Bathraspira.
The evolution of the Jurilda-Gymnothilda-Bathraspira lineage encompasses a reduction of the sculpture. However, another lineage related to Jurilda is characterized by a strengthening and complication of the ornament. Carinathilda has two primary spiral ribs and a conspicuous ornament of fine spiral ribs. It is very likely that Carinathilda originated from a Jurilda−like ancestor. Jurilda naricata naricata (Gründel, 1973) represents a transitional stage. It resembles Carina− thilda in having a strongly convex base, in the ornament of spiral ribs on the base, and in having keeled whorls. A mi− cro−ornament may be present or lacking. In any case it is weaker than in Carinathilda (Gründel 1997: 137). If the mi− cro−ornament was stronger and would form a constant charac− ter of this subspecies, then it could be placed in Carinathilda.
Angulathilda closely resembles Carinathilda. However, the base of Angulathilda is less convex and the base is demar− cated from the whorl face by a strong spiral or a pronounced edge. The keel is more pronounced in Angulathilda and the whorls are concave above and below it. These differences may be easily derived from the bauplan of Carinathilda.
Both genera seem to appear in about the same time interval, during the Bathonian.
The oldest mathildoid with three primary spiral ribs is Tricarilda. This genus is probably as old as Hettangian and certainly as old as Sinemurian. Bandel (1995) reported Late Triassic mathildoids with three primary spiral ribs but those taxa differ in several other characters and are probably not members of the family Mathildidae. Tricarilda ranges into the late Early Cretaceous and its younger fate is unknown. The genus is not present among the modern forms reported by Bieler (1995).
Mathildoids with more than three primary spiral ribs are assigned to the genus Mathilda. Such species are known from the Toarcian onward and range into the Late Cretaceous (Dockery 1993). Whether these Mesozoic forms are conge− neric with the Pliocene type species of Mathilda (see Grün− del 1976 for a re−description) and with the modern species described by Bieler (1995) remains unclear.
Turrithilda cassiana Bandel, 1995 andT. dockeryi Bandel, 1995 from the Late Triassic Cassian Formation represent mathildid species with four primary spiral ribs. These species have been assigned to Bandelthilda Gründel, 1997by Gründel (1997. They differ from Jurassic Mathilda−species in having smaller, coaxial protoconchs, two primary spiral ribs being strengthened, and angulate the whorl face; the whorls are par− allel to the shell axis between these angulations. It needs to be tested whether these species belong to the stem group of Mathilda (Nützel and Gründel in preparation).
Erratothilda resembles the Jurilda−group in having a con− spicuous micro−ornament. However, Erratothilda has three or more primary spiral ribs. Weak spiral striae are also present in some Tricarilda species (e.g., T. plana [Gründel, 1973] and T. waltheri Gründel, 1997). We therefore assume that Errato− thilda is derived from Tricarilda. Erratothilda resembles Angulathilda in shell shape (keeled whorls, concavity above and below keel, strong spiral rib at edge to base). Erratothilda has been reported from the Callovian to the Early Cretaceous. Mathildoids with a distinct micro−ornament have also been re− ported from the Late Cretaceous e.g., Echinimathilda micro− striata Dockery, 1993. In conclusion, Mathildidae are as old as Late Triassic and had a first radiation during the Late Triassic including vari− ous species and several genera. Most of these taxa became extinct at the end−Triassic mass extinction event. According to the current state of knowledge, at least one evolutionary line survived the end−Triassic extinction: the Jurilda−group. It is still unknown whether the genus Jurilda itself was pres− ent in the Late Triassic or whether closely related forms were present. Tangarilda represents an additional evolutionary lineage which probably originates as early as Late Triassic. Tricarilda is probably a descendant of the Jurilda−group. In the Early Jurassic, only a radiation on the species level can be recognized. The Pliensbachian-Toarcian crisis had no im− pact on the genus level in mathildids. Mathilda originates in the Toarcian. A distinct radiation can be recognized in the Bathonian; Gymnothilda, Carinathilda, Angulathilda, and Erratothilda appeared at about the same time. With the ex− ception of Carinathilda, these genera as well as Jurilda, Tricarilda, and Mathilda were still present in the Early Cre− taceous. Together with the Early Cretaceous Bathraspira, these genera show that Mathildidae were diverse during the period from the Middle Jurassic to the Early Cretaceous.
The evolution of the Gordenellidae in the Jurassic.- Gründel (2000) and Guzhov (2007) suggested that Pro− mathildia (= formerly Clathrobaculus) and Gordenella are closely related to each other. Promathildia has all diagnostic characters of Gordenellidae except of the concave whorl face and the ontogenetic reduction of the teleoconch ornament.
Promathildia and Gordenella share a transaxial widely exposed protoconch. In the Jurassic such protoconchs are only known from Ebalidae (see Fig. 5C , D;Schröder 1995;Gründel 1998;Kaim 2004). Even Guzhov (2007: 386) em− phasized the characteristic protoconch morphology in Gor− denella and Promathildia. This suggests that they are closely related and separates them from the Mathildidae. In sum− mary, Promathildia is here considered to represent a member of the Gordenellidae (in contrast to Gründel 2000). Accord− ing to our interpretation, this genus shows the most basal morphology of this family and represents a phylogenetic link to the Mathildidae. Guzhov's (2007) though we are aware that this phylogenetic scenario is rather hypothetical due to the insufficient knowledge of majority of involved species.
The family Gordenellidae contain only a few genera. Ap− parently, there are two evolutionary lineages. Promathildia is known since the earliest Jurassic. Very similar species which belong to Promathildia or a closely related genus haven been reported from the Late Triassic (Haas 1953). However, these species are insufficiently documented. Promathildia share some characters with the mathildid Tricarilda: three primary spiral ribs and a basically mathildoid ornament throughout its teleoconch ontogeny. Tricarilda is known since the earliest Jurassic. Promathildia is more slender and has more whorls than Tricarilda and the protoconch morphology of both gen− era differs from each other. The relationships of both genera are not yet clear. It seems possible that both genera share a last common ancestor in the Triassic. Promathildia ranges into the Early Cretaceous; its younger evolution is unknown. Several Cretaceous mathildoid gastropods were described which could belong to Gordenellidae or Mathildidae (e. g., Mathilda coxi Abbass, 1962 andM. ahmadi Abbass, 1962). However, these taxa are insufficiently known so that a safe taxonomic assignment is unwarranted.
Gordenella closely resembles Promathildia in shape, or− nament of the early teleoconch and the protoconch morphol− ogy. This suggests that Gordenella probably evolved from a Promathildia−like ancestor (Gründel 2000;Guzhov 2007). Gordenella differs from Promathildia by its pronounced ontogenetic change of the teleoconch ornament. Gordenella ranges from the Bajocian to the Oxfordian.
The yet unnamed genus and species (to be named else− where) illustrated herein (Fig. 6C) is known from the Pliens− bachian of Germany. Its early teleoconch has a "Proma− thildia−like" ornament as is typical for Gordenellidae. As in Promathildia the position of the spiral ribs remains fairly sta− ble throughout ontogeny; however, they become weaker. In contrast to Promathildia, the new genus adds numerous spiral ribs and striae during ontogeny. At the same time the axial ribs are replaced by very numerous strengthened growth lines. The ontogenetic change of the teleoconch ornament differs from that in Gordenella. The new genus and Gordenella are proba− bly not very closely related to each other. Moreover, the rela− tionship of the new genus to Promathildia is not yet clear be− cause the protoconch of the new Plienbachian genus is un− known.
The second gordenellid lineage initiates with the Late Tri− assic Camponella. Camponella closely resembles Proacirsa (Pliensbachian-Early Cretaceous) but differs in being smaller, in having fewer whorls, and in having an umbilicus. It is very likely that Proacirsa evolved from a Camponella−like ances− tor. The stratigraphic gap between the occurrences of both genera spanning the Carnian to Pliensbachian is probably a re− sult of preservation. Camponella and Proacirsa closely re− semble the genus Schafbergia Gatto   assic, Alps). Schafbergia differs from these genera in having weaker spiral ribs which are confined to the abapical portion of the whorls. Moreover, in Schafbergia, the spiral ornament on the whorl flanks persists throughout the entire ontogeny and it lacks the broadening of the spiral ribs on the base. All three genera are probably closely related to each other al− though their exact phylogenetic relationships are unknown. Turritelloidea differs from Proacirsa by its teleoconch orna− ment of broad spiral ribs and narrow furrows throughout its ontogeny (a similar ornament is present on the base of Pro− acirsa). It differs from Schafbergia in having broadened spiral ribs on mature teleoconch whorls and in details of the early whorls. The genera Camponella, Proacirsa, and Turritelloi− dea share an almost coaxial protoconch (the protoconch of Schafbergia is unknown) which differentiates them from the Promathildia−branch. Turritelloidea seems to have the longest range and originates as early as Hettangian and probably ranges into the Late Cretaceous. Seemingly, the end−Triassic crisis had no serious effect on the Gordenellidae. The Proacirsa−branch is certainly and the Promathildia−branch is probably as old as Triassic. Few new genera occur in the Jurassic and there seems to be no strong radiation of this group. Promathildia and Proacirsa are the most diverse and longest ranging genera.
Remarks on the family Anoptychiidae Bandel, 1994.-Anoptychia encompasses high−spired shells with axial ribs on the early teleoconch, which are reduced subsequently so that the shell is smooth. Bandel (1995: 16) based the new family Anoptychiidae on a heterostrophic species from the Cassian Formation, which he identified as Melania supra− plecta Münster, 1841 (type species of the genus Anoptychia Koken, 1892). However, according to Nützel (1998) and Nützel et al. (2003), Bandel (1994Bandel ( , 1995 misidentified his material. The protoconch of the type species of Anoptychia is still unknown and therefore, its higher systematic placement is doubtful. High−spired species in which teleoconch ribs are reduced during ontogeny are also present in other gastropod groups, e.g., in the family Zygopleuridae (Caenogastro− poda). Presently, it is unclear whether Anoptychia belongs to the Heterobranchia or Caenogastropoda and therefore Ano− ptychia is not considered here. The material presented by Bandel (1995) from the Late Triassic seems to represent a ge− nus which has not been reported from the Jurassic.
The Jurassic evolution of the Tofanellidae.-The knowl− edge about the Tofanellidae is rather new. Nearly all Jurassic representatives have been described since 1995. Most of them are from Germany and Poland. The Late Triassic tofa− nellids were studied by Bandel (1995). All of these species are from the Carnian Cassian Formation (N Italy). Morpho− logical details including the protoconch morphology of the minute species could only be studied after scanning electron microscopes were available. It is clear that only a small por− tion of the gone diversity of this group has been documented so far. Bandel (1995) and Gründel (1998) made first assump− tions about the relationships of fossil tofanellids to modern descendants. Kaim (2004) suggested a close phylogenetic re− lationship of tofanellids and Graphis. Bandel (2005) showed that the Recent genus Graphis belongs to the Tofanellidae and that there are closely related Jurassic forms which do not differ from their modern counterparts. Gründel (2007a, b) synonymized the Jurassic genus Rotfanella with the modern genus Graphis and thus Graphis represents an extremely long−lasting genus. There is almost no information about tofanellids from the Late Cretaceous to the Cenozoic.
Within the Tofanellidae, two groups with distinct shell morphology can be recognized. These groups may represent real phylogenetic lineages: (i) The first tofanellid group is characterized by an in− flated last protoconch whorl which is broader than the first teleoconch whorl and by a very slender, almost cylindrical teleoconch (slow increase of whorl width during ontogeny). The following genera belong to this group: Tofanella, Cri− stalloella, Graphis, Neodonaldina, and Usedomella. Tofa− nella, Cristalloella (including both subgenera), and Neo− donaldina are as old as Late Triassic. The earliest reports of Graphis and Usedomella are from the Pliensbachian. Within this group, there is a tendency to reduce the ornament. C. (Cristalloella) and some representatives of Tofanella have keeled whorls and a strong ornament of axial ribs and weaker spiral ribs. The transition from the whorl face to the base is formed by an edge with a spiral rib. Cristalloella (Won− walica) has a weaker keel and the transition from the whorl face to the base is rounded. Graphis, Neodonaldina, and Usedomella have convex, rounded whorls without keel. Graphis has a complex ornament consisting of axial and spi− ral ribs. Neodonaldina has only spiral ribs which becomes rather weak in some species. Usedomella is smooth and only some species show remains of axial ribs in the subsutural portion of the first teleoconch whorl.
(ii) The second tofanellid group encompasses the genera Camponaxis, Urlocella, Conusella, and Reinbergia. Their protoconch is not inflated and the first teleoconch whorl is broader than the teleoconch. The teleoconch is not as slender as in the first group and the whorls increase more rapidly in width so that the habitus is broader conical. The oldest known genus of this group is Camponaxis from the Late Tri− assic. The oldest known representatives of the other genera have been reported from the Pliensbachian. Camponaxis has axial and weaker spiral ribs on all teleoconch whorls. In Urlocella, the ornament is restricted to the early teleoconch whorls. Conusella and Reinbergia are smooth.
To date, five genera (subgenera) of the Tofanellidae are known from the Late Triassic. All of them survived into the Jurassic. Therefore, the end−Triassic mass extinction obvi− ously did not affect this family on the generic level. However, there is no tofanellid species which is known from the Triassic as well as from the Jurassic. On the one hand, this is preserva− tion driven because no tofanellid occurrences are known be− tween the Carnian and the Pliensbachian. On the other hand, the facies and geographic differences between the Late Trias− sic occurrences (all from the Cassian Formation) and the Ju− rassic occurrences (German−Polish Basin) make it unlikely that identical species are found before and after the Juras− sic-Triassic boundary. Seemingly, a tofanellid radiation oc− curred in the Early Jurassic. Graphis, Usedomella, Urlocella, Conusella, and Reinbergia seem to occur at about the same time in the Pliensbachian. However, it is possible or even likely that this contemporaneous appearance is result of pres− ervation and/or sampling biases. Tofanella and Reinbergia have not been reported from the post−Pliensbachian. Cristal− loella (Cristalloella), Neodonaldina, Usedomella, and Urlo− cella seem not to survive the Middle to Late Jurassic boundary according to the current state of knowledge. The younger evo− lutionary history of the Tofanellidae is largely unclear. Only Graphis is also known from the Recent.
In conclusion, the family Tofanellidae had a first radia− tion in the Late Triassic. The radiation could be somewhat older because only the Cassian Formation produces speci− mens which are so well−preserved that tofanellids can be rec− ognized whereas older Triassic formations generally lack this excellent preservation. Seemingly it was not affected by the end−Triassic crisis. A second radiation occurs in the Pliensbachian and the family reaches its highest diversity be− tween the Pliensbachian and the Callovian. Few taxa have been reported after this period. However, it must be kept in mind that tofanellids are known from very few occurrences. Graphis is a tofanellid genus which ranges from the Pliens− bachian to the Recent. This is one of the longest generic ranges known from gastropods.

Conclusions
We have presented a synoptic classification of Mesozoic (and some modern) mathildoid taxa treated herein (for a key see Appendix 1). As stated above, it is based on shell charac− ters of which the biological meaning is poorly known or un− known. In the absence of a phylogenetic framework based on anatomical and molecular studies, the present arrangement is justified especially that it largely concerns fossil taxa, which status would hardly be clarified by molecular studies. Never− theless, such studies on living mathildoids certainly would help to better understand the phylogenetic meaning and sig− nificance of shell characters in Mathildoidea. We would like to emphasize that not all Mesozoic mathildoid species are in− cluded in this classification. We omitted especially those taxa which are so poorly known that any generic and family assignment is highly speculative.
About 150 early Mesozoic (mostly Early and Middle Ju− rassic) species of the heterobranch superfamily Mathildoidea are classified into four families and 27 genera. Most taxa are assigned to the families Mathildidae, Gordenellidae, and Tofanellidae while the Triassic family Anoptychiidae holds only a single genus and is restricted to the Late Triassic. A high mathildoid diversity has been recognized from the Late Triassic Cassian Formation (Kittl 1894;Bandel 1995Bandel , 1996. Many of these taxa are unknown form the Jurassic and prob− ably became extinct during the end−Triassic mass extinction event. However, at least five genera (probably eight) sur− vived the end−Triassic mass extinction event. Tricarilda, Jurilda, and Promathildia are rather conservative, long rang− ing groups of high Jurassic species diversity. They probably gave rise to the modern Mathildidae.