Dollosuchoides
Temporal range: Middle Eocene, 47.8–41.2 Ma[1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Superfamily: Gavialoidea
Genus: †Dollosuchoides
Brochu, 2007
Type species
†Dollosuchoides densmorei
Brochu, 2007

Dollosuchoides, colloquially known as the Crocodile of Maransart, is an extinct monospecific genus of gavialoid crocodilian, traditionally regarded as a member of the subfamily Tomistominae. Fossils have been found in the Brussel Formation of Maransart, Belgium and date back to the middle Eocene.[2][3]

The holotype, IRScNB 482, was discovered in 1915 and it was prepared during 1926–1927 by M. Hubert, J. Mehschaert and M. Jean de Kleermaeker, and also in 1927, Louis Dollo had the holotype put on display in the Museum of Natural Sciences and he intended to describe the specimen but he died in 1931 before he was able to describe it and the specimen was eventually referred to Dollosuchus by Swinton (1937)[3] until it was moved to its own genus by Brochu (2007).[2][4] It is currently housed in the Gand Museum in Belgium.

Phylogeny

Below is a cladogram based morphological studies comparing skeletal features that shows Dollosuchoides as a member of Tomistominae, related to the false gharial:[5]

Crocodylidae

Crocodylinae

Tomistominae

Xaymacachampsa†

Megadontosuchus†

Kentisuchus†

Maroccosuchus†

Dollosuchoides†

Thecachampsa†

Penghusuchus†

Toyotamaphimeia†

Tomistoma cairense†

Maomingosuchus†

Tomistoma schlegelii False gharial

Gavialosuchus†

Tomistoma lusitanicum†

Paratomistoma†

Tomistoma coppensi†

Based on morphological studies of extinct taxa, the tomistomines (including the living false gharial) were long thought to be classified as crocodiles and not closely related to gavialoids.[6] However, recent molecular studies using DNA sequencing have consistently indicated that the false gharial (Tomistoma) (and by inference other related extinct forms in Tomistominae) actually belong to Gavialoidea (and Gavialidae).[7][8][9][10][11][12][13]

Below is a cladogram from a 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data that shows Dollosuchoides as a gavialoid, more basal than the last common ancestor to both the gharial and the false gharial:[12]

Gavialoidea
Gavialidae

Gavialis gangeticus Gharial

Gavialis bengawanicus†

Gavialis browni†

Gryposuchus colombianus†

Ikanogavialis†

Gryposuchus pachakamue†

Piscogavialis†

Harpacochampsa†

Toyotamaphimeia†

Penghusuchus†

Gavialosuchus†

Tomistoma lusitanicum†

Tomistoma schlegelii False gharial

(crown group)

Tomistoma cairense†

Dollosuchoides†

Maroccosuchus†

Paratomistoma†

Kentisuchus†

(total group)

References

  1. ^ Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
  2. ^ a b Brochu, C.A. (2007). "Systematics and taxonomy of Eocene tomistomine crocodylians from Britain and Northern Europe". Palaeontology. 50 (4): 917–928. doi:10.1111/j.1475-4983.2007.00679.x.
  3. ^ a b Swinton, W. E. (1937). The Crocodile of Maransart (Dollosuchus dixoni [Owen]). Mémoire 80: 3–46
  4. ^ Piras, P.; Delfino, M.; Del Favero, L.; Kotsakis, T. (2007). "Phylogenetic position of the crocodylian Megadontosuchus arduini and tomistomine palaeobiogeography". Acta Palaeontologica Polonica. 52 (2): 315–328.
  5. ^ Iijima, Masaya; Momohara, Arata; Kobayashi, Yoshitsugu; Hayashi, Shoji; Ikeda, Tadahiro; Taruno, Hiroyuki; Watanabe, Katsunori; Tanimoto, Masahiro; Furui, Sora (2018-05-01). "Toyotamaphimeia cf. machikanensis (Crocodylia, Tomistominae) from the Middle Pleistocene of Osaka, Japan, and crocodylian survivorship through the Pliocene-Pleistocene climatic oscillations". Palaeogeography, Palaeoclimatology, Palaeoecology. 496: 346–360. Bibcode:2018PPP...496..346I. doi:10.1016/j.palaeo.2018.02.002. ISSN 0031-0182.
  6. ^ Brochu, C.A.; Gingerich, P.D. (2000). "New tomistomine crocodylian from the Middle Eocene (Bartonian) of Wadi Hitan, Fayum Province, Egypt". University of Michigan Contributions from the Museum of Paleontology. 30 (10): 251–268.
  7. ^ Harshman, J.; Huddleston, C. J.; Bollback, J. P.; Parsons, T. J.; Braun, M. J. (2003). "True and false gharials: A nuclear gene phylogeny of crocodylia" (PDF). Systematic Biology. 52 (3): 386–402. doi:10.1080/10635150309323. PMID 12775527. Archived from the original (PDF) on 2022-10-09. Retrieved 2021-06-30.
  8. ^ Gatesy, Jorge; Amato, G.; Norell, M.; DeSalle, R.; Hayashi, C. (2003). "Combined support for wholesale taxic atavism in gavialine crocodylians" (PDF). Systematic Biology. 52 (3): 403–422. doi:10.1080/10635150309329. PMID 12775528.
  9. ^ Willis, R. E.; McAliley, L. R.; Neeley, E. D.; Densmore Ld, L. D. (June 2007). "Evidence for placing the false gharial (Tomistoma schlegelii) into the family Gavialidae: Inferences from nuclear gene sequences". Molecular Phylogenetics and Evolution. 43 (3): 787–794. doi:10.1016/j.ympev.2007.02.005. PMID 17433721.
  10. ^ Gatesy, J.; Amato, G. (2008). "The rapid accumulation of consistent molecular support for intergeneric crocodylian relationships". Molecular Phylogenetics and Evolution. 48 (3): 1232–1237. doi:10.1016/j.ympev.2008.02.009. PMID 18372192.
  11. ^ Erickson, G. M.; Gignac, P. M.; Steppan, S. J.; Lappin, A. K.; Vliet, K. A.; Brueggen, J. A.; Inouye, B. D.; Kledzik, D.; Webb, G. J. W. (2012). Claessens, Leon (ed.). "Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation". PLOS ONE. 7 (3): e31781. Bibcode:2012PLoSO...731781E. doi:10.1371/journal.pone.0031781. PMC 3303775. PMID 22431965.
  12. ^ a b 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.
  13. ^ Hekkala, E.; Gatesy, J.; Narechania, A.; Meredith, R.; Russello, M.; Aardema, M. L.; Jensen, E.; Montanari, S.; Brochu, C.; Norell, M.; Amato, G. (2021-04-27). "Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus". Communications Biology. 4 (1): 505. doi:10.1038/s42003-021-02017-0. ISSN 2399-3642. PMC 8079395. PMID 33907305.


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