toxodontidae

{{Automatic taxobox

| fossil_range = Late Oligocene-Holocene (Deseadan-Lujanian)
~{{Fossil range|27|0.011}}

| image = Em - Toxodon platensis - 1.jpg

| image_caption = Toxodon platensis

| image2 = Nesodon imbricatus skeleton reconstruction.jpg

| image2_caption = Skeleton of Nesodon imbricatus

| taxon = Toxodontidae

| subdivision_ranks = Subfamilies and genera

| subdivision = †Haplodontheriinae

†Nesodontinae

†Toxodontinae

| authority = Owen, 1845

}}

File:Xotodon.jpg

Toxodontidae is an extinct family of notoungulate mammals, known from the Oligocene to the Holocene (11,000 BP) of South America,{{Cite book|url=https://books.google.com/books?id=mbU-F42JU1AC&dq=Propaopus&pg=PA349|title=Holocene Extinctions|last=Turvey|first=Samuel T.|date=2009-05-28|publisher=OUP Oxford|isbn=9780191579981|language=en}} with one genus, Mixotoxodon, also known from the Pleistocene of Central America and southern North America (as far north as Texas).E. Lundelius, et al. 2013. The first occurrence of a toxodont (Mammalia, Notoungulata) in the United States. Journal of Vertebrate Paleontology, Vol 33, No 1, pp. 229–232 [https://dx.doi.org/10.1080/02724634.2012.711405 DOI:10.1080/02724634.2012.711405] Member of the family were medium to large-sized,{{Cite journal |last=Cassini |first=Guillermo H. |last2=Flores |first2=David A. |last3=Vizcaíno |first3=Sergio F. |date=July 2012 |title=Postnatal ontogenetic scaling of Nesodontine (Notoungulata, Toxodontidae) cranial morphology: Nesodontine cranial allometry |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1463-6395.2011.00501.x |journal=Acta Zoologica |language=en |volume=93 |issue=3 |pages=249–259 |doi=10.1111/j.1463-6395.2011.00501.x|hdl=11336/81335 |hdl-access=free }} ranging from around {{Convert|350–400|kg|lb}} in Nesodon to {{Convert|1000–1200|kg|lb}} in Toxodon,{{Cite journal |last=Nelson |first=Allison |last2=Engelman |first2=Russell K. |last3=Croft |first3=Darin A. |date=2023-07-12 |title=How to weigh a fossil mammal? South American notoungulates as a case study for estimating body mass in extinct clades |url=https://link.springer.com/10.1007/s10914-023-09669-1 |journal=Journal of Mammalian Evolution |language=en |doi=10.1007/s10914-023-09669-1 |issn=1064-7554|url-access=subscription }} and had medium to high-crowned dentition, which in derived members of the group evolved into ever-growing cheek teeth.{{Cite journal |last1=Gomes Rodrigues |first1=Helder |last2=Herrel |first2=Anthony |last3=Billet |first3=Guillaume |date=2017-01-31 |title=Ontogenetic and life history trait changes associated with convergent ecological specializations in extinct ungulate mammals |journal=Proceedings of the National Academy of Sciences |language=en |volume=114 |issue=5 |pages=1069–1074 |doi=10.1073/pnas.1614029114 |issn=0027-8424 |pmc=5293108 |pmid=28096389 |doi-access=free}} Isotopic analyses have led to the conclusion that Pleistocene members of the family were flexible mixed feeders (both browsing and grazing).{{Cite journal

| last = MacFadden | first = Bruce J.

| title = Diet and habitat of toxodont megaherbivores (Mammalia, Notoungulata) from the late Quaternary of South and Central America

| journal = Quaternary Research | volume = 64 | issue = 2 | pages = 113–124 | date = September 2005 | doi = 10.1016/j.yqres.2005.05.003 |bibcode = 2005QuRes..64..113M }}{{Cite journal |last=Pérez-Crespo |first=Víctor Adrián |last2=Arroyo-Cabrales |first2=Joaquín |last3=Guzmán |first3=Ana Fabiola |last4=Morales-Puente |first4=Pedro |last5=Cienfuegos-Alvarado |first5=Edith |last6=Otero |first6=Francisco J. |date=2020-01-09 |title=ISOTOPIC PALEOECOLOGY OF A TOXODONT (MIXOTOXODON LARENSIS) FROM MICHOACAN, MEXICO |url=https://bioone.org/journals/the-southwestern-naturalist/volume-64/issue-1/0038-4909-64-1-63/ISOTOPIC-PALEOECOLOGY-OF-A-TOXODONT-MIXOTOXODON-LARENSIS-FROM-MICHOACAN-MEXICO/10.1894/0038-4909-64-1-63.full |journal=The Southwestern Naturalist |volume=64 |issue=1 |pages=63 |doi=10.1894/0038-4909-64-1-63 |issn=0038-4909|url-access=subscription }}

Taxonomy

The endemic notoungulate and litoptern ungulates of South America have been shown by studies of collagen and mitochondrial DNA sequences to be a sister group to the perissodactyls.{{cite journal|last1=Welker|first1=F.|last2=Collins|first2=M. J.|last3=Thomas|first3=J. A.|last4=Wadsley|first4= M.|last5=Brace|first5 =S.|last6=Cappellini|first6=E.|last7=Turvey|first7=S. T.|last8=Reguero|first8= M.|last9=Gelfo|first9=J. N.|last10=Kramarz|first10= A.|last11=Burger|first11=J.|last12=Thomas-Oates|first12= J.|author12-link=Jane Thomas-Oates|last13= Ashford|first13=D. A.|last14=Ashton|first14=P. D.|last15= Rowsell|first15= K.|last16=Porter|first16=D. M.|last17= Kessler|first17=B.|last18= Fischer|first18=R.|last19=Baessmann|first19= C.|last20=Kaspar|first20=S.|last21=Olsen|first21=J. V.|last22= Kiley|first22=P.|last23=Elliott|first23=J. A.|last24= Kelstrup|first24=C. D.|last25=Mullin|first25= V.|last26= Hofreiter|first26=M.|last27= Willerslev|first27=E.|last28=Hublin|first28=J.-J.|last29=Orlando|first29= L.|last30= Barnes|first30=I.|last31= MacPhee|first31=R. D. E.|author2-link=Matthew Collins (academic)|author17-link=Benedikt Kessler|author27-link=Eske Willerslev|title=Ancient proteins resolve the evolutionary history of Darwin's South American ungulates|journal= Nature|date=2015-03-18|issn=0028-0836|doi= 10.1038/nature14249|volume=522|issue=7554|pages=81–84|pmid=25799987|bibcode=2015Natur.522...81W|s2cid=4467386|url=http://eprints.whiterose.ac.uk/91438/1/Welker_postprint.docx|hdl=11336/14769|hdl-access=free}}{{cite journal|last1= Buckley|first1= M.|title= Ancient collagen reveals evolutionary history of the endemic South American 'ungulates'|journal= Proceedings of the Royal Society B: Biological Sciences|volume= 282|issue= 1806|date= 2015-04-01|pages= 20142671|doi= 10.1098/rspb.2014.2671|pmid= 25833851|pmc= 4426609}}{{cite journal|last1= Westbury|first1= M.|last2= Baleka|first2= S.|last3= Barlow|first3= A.|last4= Hartmann|first4= S.|last5= Paijmans|first5=J. L. A.|last6= Kramarz|first6= A.|last7= Forasiepi|first7=A. M.|last8= Bond|first8= M.|last9= Gelfo|first9=J. N.|last10= Reguero|first10=M. A.|last11= López-Mendoza|first11= P.|last12= Taglioretti|first12= M.|last13= Scaglia|first13= F.|last14= Rinderknecht|first14= A.|last15= Jones|first15= W.|last16= Mena|first16= F.|last17= Billet|first17= G.|last18=de Muizon|first18= C.|last19= Aguilar|first19=J. L.|last20= MacPhee|first20=R. D. E.|last21= Hofreiter|first21= M.|title=A mitogenomic timetree for Darwin's enigmatic South American mammal Macrauchenia patachonica|journal=Nature Communications|volume= 8|date= 2017-06-27|pages= 15951|doi= 10.1038/ncomms15951|pmid= 28654082|pmc= 5490259|bibcode= 2017NatCo...815951W}}

In 2014, a study identifying a new species of toxodontid resolved the families' phylogenetic relations. The below cladogram was found by the study:{{Cite journal | doi = 10.1007/s12542-014-0233-5| title = New toxodontid (Notoungulata) from the Early Miocene of Mendoza, Argentina| journal = Paläontologische Zeitschrift| volume = 89| issue = 3| pages = 611–634| year = 2014| last1 = Forasiepi | first1 = A. A. M. | last2 = Cerdeño | first2 = E. | last3 = Bond | first3 = M. | last4 = Schmidt | first4 = G. I. | last5 = Naipauer | first5 = M. | last6 = Straehl | first6 = F. R. | last7 = Martinelli | first7 = A. N. G. | last8 = Garrido | first8 = A. C. | last9 = Schmitz | first9 = M. D. | last10 = Crowley | first10 = J. L. | s2cid = 129293436| url = http://sedici.unlp.edu.ar/handle/10915/127531| hdl = 11336/20443 | hdl-access = free }}

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

|1={{clade

|1=Pampahippus arenalesi

|2={{clade

|1={{clade

|1=Rhynchippus spp.

|2={{clade

|1=Scarrittia canquelensis

|2=Leonitinia gaudri }} }}

|label2=Toxodontidae

|2={{clade

|1=Proadinotherium leptognathum