Oryctorhynchus is an extinct genus of rhynchosaur from the Late Triassic (Carnian-Norian)-aged Wolfville Formation of Nova Scotia, Canada that may have been the same animal as Beesiiwo.[1] The type species, O. bairdi, was named and described in 2020.[2] It was originally seen as a species of Hyperodapedon until 2020.

Oryctorhynchus
Temporal range: Late Triassic,
~235–222 Ma
Skeletal reconstruction of O. bairdi
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Order: Rhynchosauria
Family: Rhynchosauridae
Subfamily: Hyperodapedontinae
Genus: Oryctorhynchus
Sues, Fitch & Whatley, 2020
Type species
Oryctorhynchus bairdi
Sues, Fitch & Whatley, 2020

Discovery and naming

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Left dentary of O. bairdi in A, lateral, B, medial, and C, dorsal views

The holotype was discovered in the Wolfville Formation by Donald Baird; its earliest known mention is by Baird (1963).[3] Shortly after, it was informally named the "Nova Scotia Hyperodapedon" (H. sp.) by Robin Whatley in a 1984 paper published by J. A. Hopson.[4] It was briefly described by Michael Benton (1983) also as a species of Hyperodapedon.[5] It was then assigned to cf. "Hyperodapedon" sanjuanensis by Lucas et al., (2002).[6] The genus was not recognised as a distinct taxon until it was named in 2020.[2]

The holotype, NSM018GF009.012, consists of a partial jaw and several skull fragments including the rostrum and skull roof.[2][5]

Fitch et al. (2023) state that specimen NSM018GFF009.003 has "No unique support for [being] Oryctorhynchus bairdi, and [they] do not consider it a part of O . bairdi. These attributes better align with those found in Beesiiwo cooowuse... [they] suggest it is either a close relative of Beesiiwo or a member of such."[1]

Etymology

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The genus name consists of the orycto prefix, which means burrow, and the rhynchus suffix, meaning snout; the full genus name means burrowed snout. The epithet honours David Baird, for his work on Triassic tetrapods from Nova Scotia.[2]

Classification

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Sues et al. (2020) placed Oryctorhynchus as the sister species to Hyperodapedon and an unnamed hyperodapedontine taxon from Wyoming.[2]

Paleoecology

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Oryctorhynchus is from the Wolfville Formation (Upper Wolfville Member; Fundy Basin), which probably corresponds to the Popo Agie Formation. The age of the Upper Wolfville Member is unclear; it either dates from the latest Carnian? - earliest Norian? or the late Carnian (~230 Ma).[7]

It would have coexisted with Acadiella,[8] Arctotraversodon,[9] Arctosuchus buceros (?),[10] Haligonia,[8] Scoloparia[8] and Teraterpeton.[11]

References

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  1. ^ a b Fitch, Adam; Haas, Merle; C'Hair, Wayne; Ridgley, Eugene; Ridgley, Ben; Oldman, Devin; Reynolds, Crystal; Lovelace, David (10 April 2023). "A New Rhynchosaur Taxon from the Popo Agie Formation, WY: Implications for a Northern Pangean Early-Late Triassic (Carnian) Fauna". Diversity. 15 (4): 544. doi:10.3390/d15040544. hdl:10919/114487.
  2. ^ a b c d e Hans-Dieter Sues; Adam J. Fitch; Robin L. Whatley (2020). "A new rhynchosaur (Reptilia, Archosauromorpha) from the Upper Triassic of eastern North America". Journal of Vertebrate Paleontology. 40 (2): e1771568. Bibcode:2020JVPal..40E1568S. doi:10.1080/02724634.2020.1771568. S2CID 222211622.
  3. ^ Baird, Donald (1963). "Fossil Footprints or Stump Holes?". Transactions of the Kansas Academy of Science. 66 (3): 397–400. doi:10.2307/3626532. ISSN 0022-8443. JSTOR 3626532.
  4. ^ Hopson, J.A. (1984). Late Triassic traversodont cynodonts from Nova Scotia and southern Africa. Palaeontologia Africana Vol. 25; 181-201.
  5. ^ a b Benton, M.J. (1983). The Triassic reptile Hyperodapedon from Elgin: functional morphology and relationships. Philosophical Transactions of the Royal Society of London B 302: 605-717.
  6. ^ Lucas, Spencer; Heckert, Andrew; Hotton, Nicholas (2002). "The Rhynchosaur Hyperodapedon from the Upper Triassic of Wyoming and Its Global Biochronological Significance.". Upper Triassic Stratigraphy and Paleontology: Bulletin 21. Authority of the State of New Mexico. pp. 149–157. Retrieved 11 April 2023.
  7. ^ Lucas, Spencer G.; Heckert, Andrew B.; Fraser, Nicholas C.; Huber, Philip (1999-10-21). "Aetosaurus from the Upper Triassic of Great Britain and its biochronological significance". Neues Jahrbuch für Geologie und Paläontologie - Monatshefte. 1999 (9): 568–576. doi:10.1127/njgpm/1999/1999/568. ISSN 0028-3630.
  8. ^ a b c H.-D. Sues and D. Baird. (1998). Procolophonidae (Reptilia: Parareptilia) from the Upper Triassic Wolfville Formation of Nova Scotia, Canada. Journal of Vertebrate Paleontology 18(3):525-532
  9. ^ Sues, H.-D.; Hopson, J.A.; Shubin, N.H. (1992). "Affinities of ?Scalenodontoides plemmyridon Hopson, 1984 (Synapsida: Cynodontia) from the Upper Triassic of Nova Scotia". Journal of Vertebrate Paleontology. 12 (2): 168–17. Bibcode:1992JVPal..12..168S. doi:10.1080/02724634.1992.10011447.
  10. ^ The main groups of non-mammalian synapsids at Mikko's Phylogeny Archive
  11. ^ Sues, H.-D. (2003). "An unusual new archosauromorph reptile from the Upper Triassic Wolfville Formation of Nova Scotia". Canadian Journal of Earth Sciences. 40 (4): 635–649. Bibcode:2003CaJES..40..635S. doi:10.1139/e02-048.