Acynodon

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Acynodon
Temporal range: Santonian - Maastrichtian, 86–68 Ma
Skull of Acynodon iberoccitanus (ACAP-FXl)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauria
Clade: Pseudosuchia
Clade: Crocodylomorpha
Clade: Crocodyliformes
Clade: Metasuchia
Clade: Neosuchia
Clade: Eusuchia
Genus: Acynodon
Buscalioni et al., 1997
Species
  • A. iberoccitanus Buscalioni et al., 1997 (type)
  • A. adriaticus Delfino et al., 2008
  • A. lopezi Buscalioni et al., 1997

Acynodon is an extinct genus of eusuchian crocodylomorph from the Late Cretaceous, with fossils found throughout Southern Europe.

Classification

The genus Acynodon contains three species: A. iberoccitanus, A. adriaticus, and A. lopezi. Fossils have been found in France, Spain, Italy, and Romania, dating back to the Santonian and Maastrichtian periods of the Late Cretaceous.[1]

When first described in 1997, it was placed within the family Alligatoridae.[2] New findings a decade later led to it being reclassified as a basal globidontan.[3][1] Recent studies have since resolved Acynodon as a basal eusuchian crocodylomorph, outside of the Crocodylia crown group, and a close relative to Hylaeochampsa.[4][5][6]

Description

The skull of Acynodon is extremely brevirostrine; it had a very short and broad snout compared to other known alligatorids.[3] Its dentition was quite derived, with enlarged molariform teeth and a lack of maxillary and dentary caniniform teeth, presumably an adaptation to feed on slow prey with hard shells.[1] The paravertebral osteoderms of Acynodon were distinctively double-keeled.

References

  1. ^ a b c Delfino, M.; Martin, J. E.; Buffetaut, E. (2008). "A new species of Acynodon (Crocodylia) from the Upper Cretaceous (Santonian-Campanian) of Villaggio del Pescatore, Italy". Palaeontology. 51 (5): 1091–1106. Bibcode:2008Palgy..51.1091D. doi:10.1111/j.1475-4983.2008.00800.x.
  2. ^ Buscalioni, A. D.; Ortega, F. L.; Vasse, D. (1997). "New crocodiles (Eusuchia: Alligatoroidea) from the Upper Cretaceous of southern Europe". Comptes Rendus de l'Académie des Sciences, Série IIA. 325 (7): 525–530. Bibcode:1997CRASE.325..525B. doi:10.1016/s1251-8050(97)89872-2.
  3. ^ a b Martin, J. E. (2007). "New material of the Late Cretaceous globidontan Acynodon iberoccitanus (crocodylia) from Southern France". Journal of Vertebrate Paleontology. 27 (2): 362–372. doi:10.1671/0272-4634(2007)27[362:NMOTLC]2.0.CO;2. S2CID 130433177.
  4. ^ Michael S. Y. Lee; Adam M. Yates (27 June 2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil". Proceedings of the Royal Society B. 285 (1881). doi:10.1098/rspb.2018.1071. PMC 6030529. PMID 30051855.
  5. ^ Tobias Massonne; Davit Vasilyan; Márton Rabi; Madelaine Böhme (2019). "A new alligatoroid from the Eocene of Vietnam highlights an extinct Asian clade independent from extant Alligator sinensis". PeerJ. 7: e7562. doi:10.7717/peerj.7562. PMC 6839522. PMID 31720094.
  6. ^ Blanco, A. (2021). "Importance of the postcranial skeleton in eusuchian phylogeny: Reassessing the systematics of allodaposuchid crocodylians". PLOS ONE. 16 (6): e0251900. Bibcode:2021PLoSO..1651900B. doi:10.1371/journal.pone.0251900. PMC 8189472. PMID 34106925.