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An enigmatic crocodyliform tooth from the bauxites of western Hungary suggests hidden mesoeucrocodylian diversity in the Early Cretaceous European archipelago.

Ősi A, Rabi M, Makádi L - PeerJ (2015)

Bottom Line: However, little is known about the relative timing of these faunal influences.However, East-Central European vertebrates are typically poorly known from this time period.Results.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Paleontology, Eötvös University , Budapest , Hungary ; MTA-ELTE Lendület Dinosaur Research Group , Budapest , Hungary.

ABSTRACT
Background. The Cretaceous of southern Europe was characterized by an archipelago setting with faunas of mixed composition of endemic, Laurasian and Gondwanan elements. However, little is known about the relative timing of these faunal influences. The Lower Cretaceous of East-Central Europe holds a great promise for understanding the biogeographic history of Cretaceous European biotas because of the former proximity of the area to Gondwana (as part of the Apulian microcontinent). However, East-Central European vertebrates are typically poorly known from this time period. Here, we report on a ziphodont crocodyliform tooth discovered in the Lower Cretaceous (Albian) Alsópere Bauxite Formation of Olaszfalu, western Hungary. Methods. The morphology of the tooth is described and compared with that of other similar Cretaceous crocodyliforms. Results. Based on the triangular, slightly distally curved, constricted and labiolingually flattened crown, the small, subequal-sized true serrations on the carinae mesially and distally, the longitudinal fluting labially, and the extended shelves along the carinae lingually the tooth is most similar to some peirosaurid, non-baurusuchian sebecosuchian, and uruguaysuchid notosuchians. In addition, the paralligatorid Wannchampsus also possesses similar anterior teeth, thus the Hungarian tooth is referred here to Mesoeucrocodylia indet. Discussion. Supposing a notosuchian affinity, this tooth is the earliest occurrence of the group in Europe and one of the earliest in Laurasia. In case of a paralligatorid relationship the Hungarian tooth would represent their first European record, further expanding their cosmopolitan distribution. In any case, the ziphodont tooth from the Albian bauxite deposit of western Hungary belongs to a group still unknown from the Early Cretaceous European archipelago and therefore implies a hidden diversity of crocodyliforms in the area.

No MeSH data available.


Related in: MedlinePlus

Mesoeucrocodylia indet. crocodyliform tooth (MFGI V 2015.90.2.1.) from the Lower Cretaceous (Lower Albian) Alsópere Bauxite Formation.(A) Reconstruction of the tooth in lingual view. (B) The tooth in lingual; (C) labial; (D) distal; (E) mesial; (F) apical view. (G)–(J), Details of the serrated distal carina. (K) Details of the flutings on the labial side of the tooth. Abbreviations: co, constriction between the crown and root; dg, distal groove; fl, fluting on the enamel surface; mg, mesial groove; sdc, serrated distal carina; smc, serrated mesial carina; r, root.
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fig-2: Mesoeucrocodylia indet. crocodyliform tooth (MFGI V 2015.90.2.1.) from the Lower Cretaceous (Lower Albian) Alsópere Bauxite Formation.(A) Reconstruction of the tooth in lingual view. (B) The tooth in lingual; (C) labial; (D) distal; (E) mesial; (F) apical view. (G)–(J), Details of the serrated distal carina. (K) Details of the flutings on the labial side of the tooth. Abbreviations: co, constriction between the crown and root; dg, distal groove; fl, fluting on the enamel surface; mg, mesial groove; sdc, serrated distal carina; smc, serrated mesial carina; r, root.

Mentions: The tooth (MFGI V 2015.90.2.1.) has a whitish color most probably as a result of oxidation. The central part of the crown missing, but having a pulp cavity completely filled with sediment (Fig. 2). It has a high, apically pointed, triangular, and slightly distally and lingually curved crown. The apicobasal length of the crown is 16 mm, the mesiodistal width is 5 mm and the labiolingual thickness is 3 mm; thus, the crown is slightly labiolingually flattened. The mesial and distal carinae of the crown are preserved only on the apical third and are denticulated (Figs. 2A, 2B and 2H). Following the definitions of Legasa, Buscalioni & Gasparini (1994) and Prasad & Lapparent de Broin (2002), in the case of true ziphodonts the carina is composed of isolated denticles separated by interdenticle grooves. The serration of MFGI V 2015.90.2.1. (Fig. 2G) is closer to the true ziphodont type in having individual denticles on the carinae. The interdenticle grooves of the serrated carinae are quite shallow and slightly curve ventrally towards the central region of crown (at least along the preserved apical part; Fig. 2J). Nevertheless, these denticles are clearly not the marginal prolongation of the enamel ridges as would be expected in a pseudoziphodont tooth. The outer keel of the denticles is rounded (Figs. 2G–2J). Based on the incomplete, preserved part of the carinae the average serration density on both the mesial and distal carinae is 6 denticles per mm. The lingual side of the crown bears a central convexity bordered by a pair of grooves mesially and distally, which in turn support the denticulated carinae. The distal groove is slightly wider mesiodistally than the mesial one (Figs. 2A and 2B). Similar grooves cannot be observed on the labial side of the crown. Labially, at least six shallow, longitudinal flutes occur in the basal part and terminate at the mid-length of the crown (Fig. 2C). The base of the crown is poorly preserved but on the distal side a slight constriction can be observed (Figs. 2A and 2B). The tooth base is still embedded in a piece of bauxitic matrix, but the root is visible both on the lingual and labial sides.


An enigmatic crocodyliform tooth from the bauxites of western Hungary suggests hidden mesoeucrocodylian diversity in the Early Cretaceous European archipelago.

Ősi A, Rabi M, Makádi L - PeerJ (2015)

Mesoeucrocodylia indet. crocodyliform tooth (MFGI V 2015.90.2.1.) from the Lower Cretaceous (Lower Albian) Alsópere Bauxite Formation.(A) Reconstruction of the tooth in lingual view. (B) The tooth in lingual; (C) labial; (D) distal; (E) mesial; (F) apical view. (G)–(J), Details of the serrated distal carina. (K) Details of the flutings on the labial side of the tooth. Abbreviations: co, constriction between the crown and root; dg, distal groove; fl, fluting on the enamel surface; mg, mesial groove; sdc, serrated distal carina; smc, serrated mesial carina; r, root.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4558076&req=5

fig-2: Mesoeucrocodylia indet. crocodyliform tooth (MFGI V 2015.90.2.1.) from the Lower Cretaceous (Lower Albian) Alsópere Bauxite Formation.(A) Reconstruction of the tooth in lingual view. (B) The tooth in lingual; (C) labial; (D) distal; (E) mesial; (F) apical view. (G)–(J), Details of the serrated distal carina. (K) Details of the flutings on the labial side of the tooth. Abbreviations: co, constriction between the crown and root; dg, distal groove; fl, fluting on the enamel surface; mg, mesial groove; sdc, serrated distal carina; smc, serrated mesial carina; r, root.
Mentions: The tooth (MFGI V 2015.90.2.1.) has a whitish color most probably as a result of oxidation. The central part of the crown missing, but having a pulp cavity completely filled with sediment (Fig. 2). It has a high, apically pointed, triangular, and slightly distally and lingually curved crown. The apicobasal length of the crown is 16 mm, the mesiodistal width is 5 mm and the labiolingual thickness is 3 mm; thus, the crown is slightly labiolingually flattened. The mesial and distal carinae of the crown are preserved only on the apical third and are denticulated (Figs. 2A, 2B and 2H). Following the definitions of Legasa, Buscalioni & Gasparini (1994) and Prasad & Lapparent de Broin (2002), in the case of true ziphodonts the carina is composed of isolated denticles separated by interdenticle grooves. The serration of MFGI V 2015.90.2.1. (Fig. 2G) is closer to the true ziphodont type in having individual denticles on the carinae. The interdenticle grooves of the serrated carinae are quite shallow and slightly curve ventrally towards the central region of crown (at least along the preserved apical part; Fig. 2J). Nevertheless, these denticles are clearly not the marginal prolongation of the enamel ridges as would be expected in a pseudoziphodont tooth. The outer keel of the denticles is rounded (Figs. 2G–2J). Based on the incomplete, preserved part of the carinae the average serration density on both the mesial and distal carinae is 6 denticles per mm. The lingual side of the crown bears a central convexity bordered by a pair of grooves mesially and distally, which in turn support the denticulated carinae. The distal groove is slightly wider mesiodistally than the mesial one (Figs. 2A and 2B). Similar grooves cannot be observed on the labial side of the crown. Labially, at least six shallow, longitudinal flutes occur in the basal part and terminate at the mid-length of the crown (Fig. 2C). The base of the crown is poorly preserved but on the distal side a slight constriction can be observed (Figs. 2A and 2B). The tooth base is still embedded in a piece of bauxitic matrix, but the root is visible both on the lingual and labial sides.

Bottom Line: However, little is known about the relative timing of these faunal influences.However, East-Central European vertebrates are typically poorly known from this time period.Results.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Paleontology, Eötvös University , Budapest , Hungary ; MTA-ELTE Lendület Dinosaur Research Group , Budapest , Hungary.

ABSTRACT
Background. The Cretaceous of southern Europe was characterized by an archipelago setting with faunas of mixed composition of endemic, Laurasian and Gondwanan elements. However, little is known about the relative timing of these faunal influences. The Lower Cretaceous of East-Central Europe holds a great promise for understanding the biogeographic history of Cretaceous European biotas because of the former proximity of the area to Gondwana (as part of the Apulian microcontinent). However, East-Central European vertebrates are typically poorly known from this time period. Here, we report on a ziphodont crocodyliform tooth discovered in the Lower Cretaceous (Albian) Alsópere Bauxite Formation of Olaszfalu, western Hungary. Methods. The morphology of the tooth is described and compared with that of other similar Cretaceous crocodyliforms. Results. Based on the triangular, slightly distally curved, constricted and labiolingually flattened crown, the small, subequal-sized true serrations on the carinae mesially and distally, the longitudinal fluting labially, and the extended shelves along the carinae lingually the tooth is most similar to some peirosaurid, non-baurusuchian sebecosuchian, and uruguaysuchid notosuchians. In addition, the paralligatorid Wannchampsus also possesses similar anterior teeth, thus the Hungarian tooth is referred here to Mesoeucrocodylia indet. Discussion. Supposing a notosuchian affinity, this tooth is the earliest occurrence of the group in Europe and one of the earliest in Laurasia. In case of a paralligatorid relationship the Hungarian tooth would represent their first European record, further expanding their cosmopolitan distribution. In any case, the ziphodont tooth from the Albian bauxite deposit of western Hungary belongs to a group still unknown from the Early Cretaceous European archipelago and therefore implies a hidden diversity of crocodyliforms in the area.

No MeSH data available.


Related in: MedlinePlus