Yaguarasaurus

{{Short description|Extinct genus of lizards}}

{{Automatic taxobox

| taxon = Yaguarasaurus

| fossil_range = Turonian, {{fossil_range|90}}

| image = Yaguarasaurus_columbianus_skull.jpg

| image_caption = Skull and first cervical vertebrae of Y. columbianus. Geological Museum José Royo y Gómez, Bogotá

| authority = Páramo 1994

| type_species = {{extinct}}Yaguarasaurus columbianus

| type_species_authority = Páramo 1994

| subdivision_ranks = Other species{{cite journal|author1=Rivera-Sylva, H.E.|author2=Longrich, N.R.|author3=Padilla-Gutierrez, J.M.|author4=Guzmán-Gutiérrez, J.R.|author5=Escalante-Hernández, V.M.|author6=González-Ávila, J.G.|year=2023|title=A new species of Yaguarasaurus (Mosasauridae: Plioplatecarpinae) from the Agua Nueva formation (upper Turonian – ?Lower Coniacian) of Nuevo Leon, Mexico|journal=Journal of South American Earth Sciences|volume=133 |doi=10.1016/j.jsames.2023.104694}}

| subdivision =

  • {{extinct}}Y. regiomontanus Rivera-Sylva et al., 2023

}}

Yaguarasaurus is an extinct genus of mosasauroid from the Late Cretaceous (Turonian) period of Colombia, South America. The remains discovered (an articulated skull, some vertebrae and ribs) were defined as a new genus and species of mosasaurid, Yaguarasaurus columbianus, by the Colombian paleontologist María Páramo, former director of the Museo de Geología José Royo y Gómez of INGEOMINAS in Bogotá. The first fossils remains of this animal suggested a cranial length of {{convert|47|cm|in}} and a total length of {{convert|5|m|ft}}; an additional skull that measures {{convert|87|cm|in}} long implies a larger size.{{cite journal |last=Páramo |first=M.E. |year=2000 |title=Yaguarasaurus columbianus (Reptilia, Mosasauridae), a primitive mosasaur from the Turonian (Upper Cretaceous) of Colombia |url=https://www.researchgate.net/publication/233048703 |journal=Historical Biology |volume=14 |issue=1–2 |pages=121–131 |access-date=2017-03-30 |doi=10.1080/10292380009380560|bibcode=2000HBio...14..121P |s2cid=129466921 }}

This reptile is a member of the family of marine lizards Mosasauridae characteristic of Middle and Upper Cretaceous, with global distribution, but in South America known only through isolated remains (Price, 1957, Pierce and Welles, 1959 ; Bonaparte, 1978;{{cite book |last=Bonaparte |first=J. F. |year=1978 |title=El Mesozoico de América del Sur y sus Tetrápodos |publisher=Ministerio de Cultura y Educación Fundación Miguel Lillo, San Miguel de Tucumán, Opera Lilloana |volume=26 |pages=1–596}} Ameghino, 1918). This mosasaur discovered in Yaguará, was at the moment of discovery the most complete material known in South America.{{cite journal |last=Páramo |first=M.E. |year=1994 |title=Posición sistemática de un reptil marino con base en los restos fósiles encontrados en capas del Cretácico Superior en Yaguará (Huila) |journal=Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales |volume=19 |issue=72 |pages=63–80}}

File:Yaguarasaurus regiomontanus by Nick Longrich.jpg

Etymology

The remains were found in a limestone bed (Upper Turonian) of the La Frontera Formation, member of the Villeta Group, near Yaguará, Huila, in a site called Cueva Rica.[https://paleobiodb.org/classic/displayCollResults?collection_no=122676 Yaguarasaurus columbianus] at Fossilworks.org Its name means "Yaguará lizard of Colombia".

Phylogeny

File:Blakey 090Ma - COL.jpg

The following cladograms illustrate the phylogenetic analyses of two competing hypotheses on the classification of Yaguarasaurus. Topology A represents the traditional view of the genus belonging to the subfamily Yaguarasaurinae following Palci et al. (2013).{{cite journal | last1 = Palci | first1 = A. | last2 = Caldwell | first2 = M. W. | last3 = Papazzoni | first3 = C. A. | doi = 10.1080/02724634.2013.731024 | title = A new genus and subfamily of mosasaurs from the Upper Cretaceous of northern Italy | journal = Journal of Vertebrate Paleontology | volume = 33 | issue = 3 | pages = 599 | year = 2013 | bibcode = 2013JVPal..33..599P | s2cid = 86646993 }} Topology B follows Rivera-Sylva et al. (2023) and depicts a new hypothesis holding Yaguarasaurus as a basal member of the Plioplatecarpinae, which was first proposed by Polcyn et al. (2023) based on the discovery of symapomorphies in the braincase.{{Cite journal |last1=Polcyn |first1=Michael J. |last2=Bardet |first2=Nathalie |last3=Albright III |first3=L. Barry |last4=Titus |first4=Alan |date=2023 |title=A new lower Turonian mosasaurid from the Western Interior Seaway and the antiquity of the unique basicranial circulation pattern in Plioplatecarpinae |journal=Cretaceous Research |volume=151 |doi=10.1016/j.cretres.2023.105621 |doi-access=free |bibcode=2023CrRes.15105621P }}

In the second scenario, the two species of Yaguarasaurus are paraphyletic with respect to more derived plioplatecarpines, with Y. regiomontanus lying further up the tree.

{{clade gallery |width=450px |height=550px

|caption1=Topology A

|header1=Yaguarasaurine per Palci et al. (2013) File:Yaguarasaurus columbianus tethysaur MP.png

|cladogram1={{clade| style=font-size:85%;line-height:95%

|label1=Russellosaurina

|1={{clade

|1={{clade

|label1=Tethysaurinae

|1={{clade

|1=Tethysaurus nopscai

|2=Pannoniasaurus inexpectatus

}}

|label2=Yaguarasaurinae

|2={{clade

|1=Yaguarasaurus columbianus

|2={{clade

|1=Russellosaurus coheni

|2=Romeosaurus fumanensis

}}

}}

}}

|2={{clade

|label1=Plioplatecarpinae

|1={{clade

|1={{clade

|1=Angolasaurus bocagei

|2={{clade

|1=Selmasaurus johnsoni

|2=Ectenosaurus clidastoides

}}

}}

|2={{clade

|1=Plesioplatecarpus planiforms

|2={{clade

|1=Latoplatecarpus willistoni

|2={{clade

|1=Platecarpus tympanticus

|2=Plioplatecarpus spp.

}}

}}

}}

}}

|2=Tylosaurinae

}}

}}

}}

|caption2=Topology B

|header2=Basal plioplatecarpine per Rivera-Sylva et al. (2023) File:Yaguarasaurus columbianus plioplatecarpine MP.png

|cladogram2={{clade| style=font-size:85%;line-height:95%

|label1=Plioplatecarpinae

|1={{clade

|1=Tethysaurus nopscai

|2={{clade

|1=Russellosaurus coheni

|2={{clade

|1=Yaguarasaurus columbianus

|2={{clade

|1=KUVP 97200

|2={{clade

|1=Yaguarasaurus regiomontanus

|2={{clade

|1={{clade

|1=Ectenosaurus everhartorum

|2=Ectenosaurus clidastoides

}}

|2={{clade

|1=Angolasaurus bocagei

|2={{clade

|1={{clade

|1=Plesioplatecarpus planiforms

|2={{clade

|1=Platecarpus tympanticus

|2={{clade

|1=Latoplatecarpus willistoni

|2={{clade

|1=Plioplatecarpus nichollsae

|2={{clade

|1=Plioplatecarpus brachycephalus

|2={{clade

|1=Plioplatecarpus coryphaeus

|2=Plioplatecarpus primaevus

|3={{clade

|1=Plioplatecarpus peckensis

|2=Plioplatecarpus houzeaui

|3=Plioplatecarpus marshi

}}

}}

}}

}}

}}

}}

}}

|2={{clade

|1=Selmasaurus johnsoni

|2={{clade

|1=Selmasaurus russelli

|2={{clade

|1=Gavialimimus almaghribensis

|2=Goronyosaurus nigeriensis

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

See also

{{Portal|Paleontology}}

References

{{Reflist}}