Rutiodon

{{Short description|Extinct genus of reptiles}} {{Automatic taxobox | fossil_range = {{Fossil range|237|208.5}} | image = Rutiodon carolinensis AMNH.jpg | image_upright = 1.15 | image_caption = Skeleton of ''Rutiodon carolinensis'' (AMNH 1) in the [[American Museum of Natural History]] | taxon = Rutiodon | authority = [[Ebenezer Emmons|Emmons]], 1856 | subdivision_ranks = Species | subdivision = *{{extinct}}'''''R. carolinensis''''' (Emmons, 1856) ([[type species|type]]) *{{extinct}}'''''R. manhattanensis''''' (Huene, 1913) | synonyms = *''Palaeonornis'' Emmons, 1857 }}

'''''Rutiodon''''' (meaning "wrinkle tooth") is an [[extinct]] [[genus]] of [[mystriosuchine]] [[Phytosaur|phytosaurs]] from the [[Late Triassic]] of the eastern [[United States]].<ref name="Stocker2010">{{cite journal|author=Michelle R. Stocker |year=2010 |title=A new taxon of phytosaur (Archosauria: Pseudosuchia) from the Late Triassic (Norian) Sonsela Member (Chinle Formation) in Arizona, and a critical reevaluation of ''Leptosuchus'' Case, 1922 |journal=Palaeontology |volume=53 |issue=5 |pages=997–1022 |doi=10.1111/j.1475-4983.2010.00983.x |doi-access=free }}</ref> The type species of ''Rutiodon'', ''Rutiodon carolinensis'', encompasses a large number of skulls and assorted postcranial fossils discovered in the [[Cumnock Formation]] of [[North Carolina]]. Fossils referable to the species are also known from [[Pennsylvania]], [[New Jersey]], and [[Virginia]]. ''Rutiodon carolinensis'' is the most well-described species of phytosaur in eastern North America, though its validity as a [[Natural group|natural]] [[taxon]] has been questioned. Some paleontologists also recognize a larger and more robust species, ''Rutiodon manhattanensis'', which is known from teeth and postcranial fossils from New Jersey and Pennsylvania.

==Description== [[File:Rutiodon.jpg|thumb|left|Skeletal diagram of ''Rutiodon manhattanensis'', with preserved portions of the skeleton in grey]] Like other [[phytosaur]]s, ''Rutiodon'' strongly resembled a [[crocodile]], but its nostrils were positioned far back on the head, close to the eyes, instead of at the tip of the snout. It had enlarged front teeth, and a relatively narrow jaw, somewhat resembling that of a modern [[gharial]]. This suggests that this [[carnivore]] probably caught fish and it may also have snatched land animals (such as ''[[Coelophysis]]'') from the waterside.<ref name=RMG01/> Also, like modern crocodiles, its back, flanks, and tail were covered with bony [[osteoderm|armored plate]]s.<ref name=EoDP>{{cite book |editor=Palmer, D.|year=1999 |title= The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals|publisher= Marshall Editions|location=London|page= 95|isbn= 1-84028-152-9}}</ref>

''Rutiodon'' was among the largest carnivorous animals of its environment, measuring up to {{convert|8|m|ft}} long and weighing about {{convert|1|MT|ST}}.<ref name="RMG01">{{cite book |first=Richard M.|last=Gaines|title=Coelophysis|year=2001 |publisher= ABDO Publishing Company|page= 21|isbn= 1-57765-488-9}}</ref><ref>{{Cite journal |last1=Hartman |first1=Scott A. |last2=Lovelace |first2=David M. |last3=Linzmeier |first3=Benjamin J. |last4=Mathewson |first4=Paul D. |last5=Porter |first5=Warren P. |date=November 2022 |title=Mechanistic Thermal Modeling of Late Triassic Terrestrial Amniotes Predicts Biogeographic Distribution |journal=Diversity |language=en |volume=14 |issue=11 |page=973 |doi=10.3390/d14110973 |issn=1424-2818|doi-access=free }}</ref>

==Species==

=== ''R. carolinensis'' === {{multiple image | perrow = 1/1 | total_width = 250 | image1 = Rutiodon fossil.jpg | image2 = Rutiodon BW.jpg | footer = AMNH fossil (top) and life restoration (bottom) of ''Rutiodon carolinensis'' | align = left }}

The [[type species]] of ''Rutiodon'' is ''R. carolinensis''. It was originally named by [[Ebenezer Emmons]] in 1856, based on fossils from the Deep River coal field ([[Cumnock Formation]])<ref name=":0">{{Cite journal |last=Gregory |first=Joseph T. |date=27 June 1962 |title=The Relationships of the American Phytosaur ''Rutiodon'' |url=https://digitallibrary.amnh.org/bitstream/handle/2246/3397/N2095.pdf?sequence=1 |journal=American Museum Novitates |issue=2095 |pages=1–22 |archive-url=https://web.archive.org/web/20230212205500/https://digitallibrary.amnh.org/bitstream/handle/2246/3397/N2095.pdf?sequence=1 |archive-date=12 February 2023}}</ref> of North Carolina. The original fossils include five striated teeth and associated vertebrae, ribs, and [[interclavicle]] fragments.<ref name=":0" />

Later, Emmons (1860) mentioned that he had discovered a nearly complete skull of ''R. carolinensis'' from North Carolina, at the time the most complete phytosaur skull known from the United States. It is also the largest skull referred to ''Rutiodon'', at a length of 77.3 cm (30.4 inches).<ref name="CRutiodon" /> This skull was described in more detail by [[Edwin H. Colbert]] in 1947.<ref>{{Cite journal |last=Colbert |first=Edwin Harris |date=1947 |title=Studies of the phytosaurs ''Machaeroprosopus'' and ''Rutiodon'' |url=https://digitallibrary.amnh.org/handle/2246/395 |journal=Bulletin of the American Museum of Natural History |volume=88 |issue=2|hdl=2246/395 }}</ref> Emmons' phytosaur skull was originally stored in the [[Williams College]] geological museum,<ref name=":0" /><ref name="CRutiodon" /> and was later transferred to the [[National Museum of Natural History]] (USNM).<ref name=":1">{{Cite journal |last1=Doyle |first1=Kevin D. |last2=Sues |first2=Hans-Dieter |date=1995-09-14 |title=Phytosaurs (Reptilia: Archosauria) from the Upper Triassic New Oxford Formation of York County, Pennsylvania |url=|journal=Journal of Vertebrate Paleontology |language=en |volume=15 |issue=3 |pages=545–553 |doi=10.1080/02724634.1995.10011247 |issn=0272-4634}}</ref> Many skulls and partial skeletons of ''R. carolinensis'' have been discovered near [[Cumnock, North Carolina|Egypt, North Carolina]], and are now housed and displayed at the [[American Museum of Natural History]] (AMNH).<ref name=":0" /> [[File:Rutiodon carolinensis AMNH 1 anterior.jpg|upright|thumb|Skeletal mount of ''R. carolinensis'' (AMNH 1) viewed from the front]] In 1963, a small partial phytosaur skull (AMNH 5500) was discovered at the [[Granton Junction|Granton Quarry]] of [[North Bergen, New Jersey]]. This skull, recovered from grey [[argillite]] of the [[Lockatong Formation]], was described by Colbert in 1965. He identified the skull as a probable juvenile specimen of ''R. carolinensis''.<ref name="CRutiodon">{{Cite journal |last=Colbert |first=Edwin H. |date=10 September 1965 |title=A Phytosaur from North Bergen, New Jersey |url=http://digitallibrary.amnh.org/bitstream/handle/2246/3324/N2230.pdf?sequence=1 |journal=American Museum Novitates |issue=2230 |pages=1–25 |archive-url=https://web.archive.org/web/20160302115359/http://digitallibrary.amnh.org/bitstream/handle/2246/3324/N2230.pdf?sequence=1 |archive-date=2 March 2016}}</ref> Doyle and Sues (1995) described a well-preserved phytosaur skull ([[State Museum of Pennsylvania|SMP]] VP-45) from the [[New Oxford Formation]] in [[York County, Pennsylvania]]. This skull was very similar to skulls previously referred to ''R. carolinesis''. They considered ''R. carolinensis'' to be an undiagnostic species, as it was originally diagnosed based on teeth. According to these authors, "''Rutiodon''" is a metataxon of eastern phytosaurs for which [[monophyly]] cannot be established.<ref name=":1" />

Since its original description, ''R. carolinensis'' has been conflated with various other phytosaur species from the eastern United States. [[Isaac Lea]] named several phytosaur species from [[Pennsylvania]] shortly before Emmons' description: ''[[Clepsysaurus|Clepsysaurus pennsylvanicus]]'' (in 1851) and ''[[Centemodon|Centemodon sulcatus]]'' (in 1856). Both species were compared favorably with ''R. carolinensis'' by Emmons, and some authors have noted that either could be considered a [[senior synonym]] of ''Rutiodon''. Nevertheless, fossils of ''R. carolinensis'' are much more complete, so the validity of the genus is rarely questioned. ''Clepsysaurus'' and ''Centemodon'' are most commonly considered dubious and undiagnostic, and their fossils have variably been referred to ''Rutiodon'', ''[[Phytosaurus]]'', or Phytosauria incertae sedis by different authors.<ref name=":0" /><ref name=":4">{{Cite journal |last=Gregory |first=J. T. |date=1962-11-01 |title=The genera of phytosaurs |url=https://ajs.scholasticahq.com/article/58959 |journal=American Journal of Science |language=en |volume=260 |issue=9 |pages=652–690 |doi=10.2475/ajs.260.9.652 |issn=0002-9599|doi-access=free }}</ref><ref name="CRutiodon" />

[[Othniel Charles Marsh]] (1893) named ''[[Belodon|Belodon validus]]'', based on a scapula from the [[New Haven Arkose]] near [[Simsbury, Connecticut]].<ref name="Marsh1893">Marsh, O.C. (1893). "Restoration of ''Anchisaurus''". ''The American Journal of Science''. Series 3 45: 169-170.</ref> In 1896, Marsh mentioned a phytosaur skull from [[Chatham County, North Carolina]]. This was the second phytosaur skull found in the area, after that of Emmons (1860). Marsh named his phytosaur skull ''Rhytidodon rostratus''. ''Belodon validus'' is considered dubious and undiagnostic,<ref name="CRutiodon" /> while ''"Rhytidodon rostratus''" (specimen USNM 5373) has been referred to ''R. carolinensis''.<ref name=":0" />

Phytosaur fossils tentatively referred to ''R. carolinensis'' were unearthed in 1959 in [[Fairfax County, Virginia]], near [[Dulles International Airport]] which was still under construction. These fossils, including vertebrae, ribs, and scutes, were recovered from red calcareous mudstones of the [[Ball's Bluff Siltstone]]. This extends the range of ''Rutiodon'' (and phytosaurs as a whole) into the [[Culpeper Basin]].<ref>{{Cite journal |last=Weems |first=Robert E. |date=16 November 1979 |title=A large parasuchian (phytosaur) from the Upper Triassic portion of the Culpeper Basin of Virginia (USA) |url=https://www.researchgate.net/publication/236107027 |journal=Proceedings of the Biological Society of Washington |volume=92 |issue=4 |pages=682–688}}</ref>

=== ''R. manhattanensis'' === [[File:Rutiodon manhattanensis holotype.jpg|thumb|The [[holotype]] of ''R. manhattanensis'' on display in the [[American Museum of Natural History]]|left]]Fossils of a second species, ''R. manhattanensis'', were discovered in 1910 from "red sandy marl" ([[Stockton Formation]])<ref name="CRutiodon" /><ref name=":1" /> below the [[The Palisades (Hudson River)|Palisades]] near [[Fort Lee, New Jersey]]. In 1913, it was described by [[Friedrich von Huene]], who provided a new species name in reference to its close proximity to [[Manhattan]]. The fossil is a partially articulated posterior torso, including the hip, hind limbs (missing the feet), and portions of the tail and scutes. It was differentiated from ''R. carolinensis'' based on a proportionally larger [[tibia]] and more robust hip. ''R. manhattanensis'' is also noticeably larger in size: Huene remarked that the holotype has the largest femur he had ever observed in phytosaurs, at a length of 43-44 cm (17 inches).<ref>{{Cite journal |last=Huene |first=Friedrich R. |date=1913 |title=A new phytosaur from the Palisades near New York |url=https://digitallibrary.amnh.org/handle/2246/1411 |journal=Bulletin of the American Museum of Natural History |language=en-US |volume=32 |issue=15|hdl=2246/1411 }}</ref>

Some authors have referred ''R. manhattanensis'' to ''"Clepsysaurus"''<ref name=":0" /> or ''Phytosaurus'',<ref name=":4" /> but its referral to ''Rutiodon'' was upheld by Colbert (1965).<ref name="CRutiodon" /> Very large phytosaur teeth, osteoderms, and hindlimb fossils (specimen [[Peabody Museum of Natural History|YPM]]-[[Princeton University|PU]] 11544) from [[York, Pennsylvania]] have also been referred to ''R. manhattanensis''.<ref name="CRutiodon" /><ref name=":1" /> A few authors have doubted the validity of ''R. manhattanensis'', arguing that the differences between the two species may be due to [[sexual dimorphism]].<ref name=":1" />

==Classification== The exact relationship between ''Rutiodon'' and other phytosaurs has gone through much revision.<ref name=":4" /><ref name=":5">{{Cite journal |last1=Jones |first1=Andrew S. |last2=Butler |first2=Richard J. |date=2018-12-10 |title=A new phylogenetic analysis of Phytosauria (Archosauria: Pseudosuchia) with the application of continuous and geometric morphometric character coding |journal=PeerJ |language=en |volume=6 |article-number=e5901 |doi=10.7717/peerj.5901 |pmid=30581656 |issn=2167-8359|pmc=6292387 |doi-access=free }}</ref>

Several papers in the late 20th century extended the scope of the genus ''Rutiodon'', allowing it to encompass phytosaur species from both the eastern and western United States. Western species lumped into ''Rutiodon'' include nearly all species previously placed into the genera ''[[Leptosuchus]]'', ''[[Machaeroprosopus]]'', and ''[[Pseudopalatus]]''.<ref name=":0" /><ref name=":4" /><ref name=":2">Ballew, K. L. (1989). "A phylogenetic analysis of Phytosauria from the Late Triassic of the western United States". In: Lucas, S. G. and Hunt, A. P., eds., ''Dawn of the age of dinosaurs in the American Southwest'', pp. 309-339. New Mexico Museum of Natural History. Albuquerque.</ref> A 1995 paper, and most subsequent studies on phytosaurs, disagreed with the idea that ''Rutiodon'' encompassed western phytosaur species.<ref name=":3" /> The authors re-instated the validity of ''Machaeroprosopus'' (with ''Pseudopalatus'' as a [[junior synonym]]) and ''Leptosuchus''. They also created the new genus ''[[Smilosuchus]]'' for "''Machaeroprosopus" gregorii''.<ref name=":3">Long, R. A., and Murry, P. A. (1995). Late Triassic (Carnian and Norian) tetrapods from the southwestern United States. ''New Mexico Museum of Natural History and Science Bulletin'' '''4''':1-254.</ref>

Recent papers agree that ''Rutiodon'' occupies a tier of the phytosaur family tree more derived than ''[[Paleorhinus]]'' and less derived than ''[[Leptosuchus]]''.<ref name="Stocker2010" /><ref name="SMR122" /><ref name=":03">{{Cite journal |author1=Christian F. Kammerer |author2=Richard J. Butler |author3=Saswati Bandyopadhyay |author4=Michelle R. Stocker |year=2016 |title=Relationships of the Indian phytosaur ''Parasuchus hislopi'' Lydekker, 1885 |url=http://pure-oai.bham.ac.uk/ws/files/19880739/Kammerer_et_al._2015._Accepted_MS.pdf |journal=Papers in Palaeontology |volume=2 |issue=1 |pages=1–23 |doi=10.1002/spp2.1022 |s2cid=83780331}}</ref><ref name=":5" /> In other words, ''Rutiodon'' lies within the large [[clade]] [[Phytosauridae]]<ref name="Stocker2010" /> (alternatively known as [[Mystriosuchinae]])<ref name=":03" /> and outside the less inclusive clade [[Leptosuchomorpha]].<ref name="Stocker2010" /> A 2001 conference abstract argued that ''Rutiodon carolinensis'' was a synonym of ''[[Angistorhinus]]'',<ref>Hungerbühler, A. and Sues, H.-D. (2001). Status and phylogenetic relationships of the Late Triassic phytosaur ''Rutiodon carolinensis''. ''Journal of Vertebrate Paleontology'' ''21''(3 suppl.):64A.</ref> mirroring older suggestions that ''Angistorhinus'' was directly ancestral to ''Rutiodon''.<ref name=":4" /> This interpretation of synonymy has not been formally published. A 2018 analysis of phytosaur relationships did support a placement for ''Rutiodon carolinensis'' as the [[sister taxon]] of ''Angistorhinus'' in a clade at the base of Mystriosuchinae.<ref name=":5" /> Later papers describing ''[[Volcanosuchus]]'' and ''[[Colossosuchus]]'', two basal mystriosuchines from the [[Tiki Formation]] of [[India]], did not support a sister group relationship between ''Angistorhinus'' and ''Rutiodon''. Instead, ''Angistorhinus'' was consistently placed as sister to ''[[Brachysuchus]]''. ''Rutiodon'' was usually recovered as closer to (but still outside) Leptosuchomorpha.<ref>{{Cite journal |last1=Datta |first1=Debajit |last2=Ray |first2=Sanghamitra |last3=Bandyopadhyay |first3=Saswati |date=2021 |editor-last=Smith |editor-first=Andrew |title=Cranial morphology of a new phytosaur (Diapsida, Archosauria) from the Upper Triassic of India: implications for phytosaur phylogeny and biostratigraphy |url=https://zenodo.org/record/4274207|journal=Papers in Palaeontology |language=en |volume=7 |issue=2 |pages=675–708 |doi=10.1002/spp2.1292 |s2cid=213698017 |issn=2056-2799}}</ref><ref name=":6">{{Cite journal |last1=Datta |first1=Debajit |last2=Ray |first2=Sanghamitra |date=2023 |editor-last=Field |editor-first=Daniel |title=A giant phytosaur (Diapsida, Archosauria) from the Upper Triassic of India with new insights on phytosaur migration, endemism and extinction |url=|journal=Papers in Palaeontology |language=en |volume=9 |issue=1 |doi=10.1002/spp2.1476 |s2cid=257103850 |issn=2056-2799}}</ref> Over half of the most parsimonious trees in the 2023 description of ''Colossosuchus'' positioned ''Rutiodon'' as the sister taxon to ''[[Volcanosuchus]]''.<ref name=":6" />

Below is a [[cladogram]] from Stocker (2012):<ref name=SMR122>{{Cite journal | last1 = Stocker | first1 = M. R. | title = A new phytosaur (Archosauriformes, Phytosauria) from the Lot's Wife beds (Sonsela Member) within the Chinle Formation (Upper Triassic) of Petrified Forest National Park, Arizona | doi = 10.1080/02724634.2012.649815 | journal = Journal of Vertebrate Paleontology | volume = 32 | issue = 3 | pages = 573–586 | year = 2012 | s2cid = 129527672 }}</ref>

{{clade| style=font-size:100%;line-height:85% |label1=[[Phytosauria]] |1={{clade |1=''[[Paleorhinus scurriensis|"Paleorhinus" scurriensis]]'' |2={{clade |1=''[[Paleorhinus bransoni]]'' |2={{clade |1=''[[Paleorhinus|"Paleorhinus" sawini]]'' |label2=[[Phytosauridae]] |2={{clade |1=''[[Brachysuchus megalodon]]'' |2=''[[Angistorhinus]]'' |3={{clade |1='''''Rutiodon carolinensis''''' |2=''"Machaeroprosopus" zunii'' |3=''[[Protome batalaria]]'' |label4=[[Leptosuchomorpha]] |4={{clade |1=''[[Phytosaurus|"Phytosaurus" doughtyi]]'' |2=TMM 31173-120 |3={{clade |1=''[[Leptosuchus crosbiensis]]'' |2=''[[Leptosuchus studeri]]''}} |4={{clade |1={{clade |1=''[[Smilosuchus lithodendrorum]]'' |2={{clade |1=''[[Smilosuchus adamanensis]]'' |2=''[[Smilosuchus gregorii]]''}} }} |2={{clade |1=''[[Pravusuchus hortus]]'' |label2=[[Pseudopalatinae]] |2={{clade |1=''[[Pseudopalatus mccauleyi]]'' |2={{clade |1=''[[Mystriosuchus westphali]]'' |2=''[[Pseudopalatus pristinus]]'' }} }} }} }} }} }} }} }} }} }} }}

==References== {{Reflist}}

==External links== * [http://docsouth.unc.edu/nc/emmonsml/emmons.html Geological report of the midland counties of North Carolina] by Ebenezer Emmons. New York, G.P. Putnam & Co.; Raleigh, H.D. Turner, 1856.

[[Category:Phytosauria]] [[Category:Prehistoric reptile genera]] [[Category:Late Triassic reptiles of North America]] [[Category:Triassic geology of New Jersey]] [[Category:Fossils of New Jersey]] [[Category:Triassic geology of New York (state)]] [[Category:Paleontology in New York (state)]] [[Category:Triassic geology of North Carolina]] [[Category:Fossils of North Carolina]] [[Category:Fossil taxa described in 1856]] [[Category:Taxa named by Ebenezer Emmons]]