Powellophis

{{Short description|Extinct madtsoiid snake}} {{Speciesbox | name = ''Powellophis'' | fossil_range = Selandian-Thanetian, {{Fossil range|61|57}} | genus = Powellophis | species = andina<ref name="description" /> | authority = Garberoglio, Triviño & Albino, 2022<ref name="description" /> }}

'''''Powellophis''''' is a genus of extinct madtsoiid snake from the Mealla Formation of Argentina, dating back to the Paleocene. It is a monospecific genus, with the only species being '''''P. andina'''''.

==Discovery and naming== The holotype of ''Powellophis'', specimen '''PVL 4714''', preserves a nearly complete and articulated skeleton in nine continuous siltstone blocks. However, only blocks 4714-2 to 4714-9 were available for study. This means that other blocks from the holotype specimen are not included in the paper naming the genus. The animal shares some features of its vertebral morphology with other mid to large sized madtsoiids. ''Powellophis'' is quantitatively estimated to have been around {{cvt|3|m|ft}} in length based on measures of vertebrae and total length in extant snakes.<ref name="description" />

The genus name ''Powellophis'' means "Jaime Powell's Snake". The name is constructed from the words Powell and {{lang|grc-Latn|ophis}}, the former in honor of the late Dr. Jaime Powell who recovered the specimen and the latter meaning snake in Ancient Greek. The specific name ''andina'' is named for the Andes region of Northwestern Argentina, where the fossil remains of the animal were discovered.<ref name="description">{{Cite journal |last1=Garberoglio |first1=Fernando F. |last2=Triviño |first2=Laura N. |last3=Albino |first3=Adriana |date=2022-11-15 |title=A new madtsoiid snake from the Paleogene of South America (northwestern Argentina), based on an articulated postcranial skeleton |journal=Journal of Vertebrate Paleontology |volume=42 |issue=2 |doi=10.1080/02724634.2022.2128687 |bibcode=2022JVPal..42E8687G |s2cid=253566068 |issn=0272-4634|hdl=11336/200815 |hdl-access=free }}</ref>

==Classification== In the phylogeny from Garberoglio, Triviño & Albino (2022), ''Powellophis'' is recovered as a sister taxon to ''Eomadtsoia'' and a basal member of a clade that includes most large bodied and gigantic members of the group like ''Gigantophis'', ''Wonambi'', and ''Madtsoia''.<ref name="description" /> A clade with similar genus composition, although lacking ''Powellophis'', was recovered in 2019 by Gómez, Garberoglio & Rougier.<ref>{{Cite journal |last1=Gómez |first1=Raúl O. |last2=Garberoglio |first2=Fernando F. |last3=Rougier |first3=Guillermo W. |date=2019-10-01 |title=A new Late Cretaceous snake from Patagonia: Phylogeny and trends in body size evolution of madtsoiid snakes |journal=Comptes Rendus Palevol |series=Palaeobiology and palaeobiogeography of amphibians and reptiles: An homage to Jean-Claude Rage |language=en |volume=18 |issue=7 |pages=771–781 |doi=10.1016/j.crpv.2019.09.003 |issn=1631-0683|doi-access=free |bibcode=2019CRPal..18..771G |hdl=11336/139595 |hdl-access=free }}</ref>

==Paleoenvironment== ''Powellophis'' inhabited the Mealla Formation, dating to the middle to late paleocene of Northwestern Argentina. The preserved vertebrate fauna from this formation includes teleostean fishes, pelomedusid turtles, sebecid crocodillians and notoungulate mammals.<ref>{{Cite journal |last1=Pascual |first1=R. |last2=Vucetich |first2=M. G. |last3=Fernández |first3=J. |date=2013 |title=Los primeros mamíferos (Notoungulata, Henricosborniidae) de la Formación Mealla (grupo Salta, subgrupo Santa Bárbara). Sus implicancias filogenéticas, taxonómicas y cronológicas. |url=https://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/1566 |journal=Ameghiniana |volume=15 |issue=3–4 |pages=366–390 }}</ref><ref>{{Cite journal |last1=Kulik |first1=A. M. |last2=Kondrat'eva |first2=L. N. |date=1975 |title=[Combined effects of hypoxia and hypercapnia on the functional state of the respiratory center] |journal=Biulleten' Eksperimental'noi Biologii I Meditsiny |volume=79 |issue=4 |pages=39–43 |issn=0365-9615 |pmid=103}}</ref><ref>{{Cite journal |last1=Bravo |first1=Gonzalo Gabriel |last2=Pol |first2=Diego |last3=García-López |first3=Daniel A. |date=2021-05-04 |title=A new sebecid mesoeucrocodylian from the Paleocene of northwestern Argentina |journal=Journal of Vertebrate Paleontology |volume=41 |issue=3 |article-number=e1979020 |doi=10.1080/02724634.2021.1979020 |bibcode=2021JVPal..41E9020B |s2cid=240087442 |issn=0272-4634|hdl=11336/166549 |hdl-access=free }}</ref> The environmental interpretation indicates the presence of a sandy, meandering fluvial system with low energy and low sinuosity, mud dominated floodplains with paleosol development, and shallow, freshwater clastic lakes with periods of subaerial exposure.<ref>{{Cite journal |last1=del Papa |first1=Cecilia |last2=Babot |first2=Judith |last3=Dahlquist |first3=Juan |last4=López |first4=Daniel García |last5=Deraco |first5=Virginia |last6=Herrera |first6=Claudia |last7=Bertelli |first7=Sara |last8=Rougier |first8=Guillermo W. |last9=Giannini |first9=Norberto P. |date=2022-01-01 |title=Toward a chronostratigraphy of the Paleocene-Eocene sedimentary record in northwestern Argentina |url=https://www.sciencedirect.com/science/article/pii/S0895981121005228 |journal=Journal of South American Earth Sciences |language=en |volume=113 |article-number=103677 |doi=10.1016/j.jsames.2021.103677 |bibcode=2022JSAES.11303677D |s2cid=245310455 |issn=0895-9811|url-access=subscription |hdl=11336/198516 |hdl-access=free }}</ref>

== References == {{Reflist}}

Category:Paleocene reptiles of South America Category:Fossils of Argentina Category:Fossil taxa described in 2022 Category:Selandian Category:Thanetian Category:Prehistoric reptile genera Category:Paleogene Argentina