Editing Deer (section)

===Eocene===

The [[ruminant]]s, ancestors of the Cervidae,<!--not sure how much we should say on this in this article--> are believed to have evolved from ''[[Diacodexis]]'', the earliest known artiodactyl (even-toed ungulate), 50–55 Mya in the Eocene.<ref name=Janis1998/> ''Diacodexis'', nearly the size of a [[rabbit]], featured the [[talus bone]] characteristic of all modern [[even-toed ungulate]]s. This ancestor and its relatives occurred throughout North America and Eurasia, but were on the decline by at least 46 Mya.<ref name="Janis1998">{{cite book | last1=Janis | first1=C. M. | last2=Effinger | first2=J. A. | last3=Harrison | first3=J. A. | last4=Honey | first4=J. G. | last5=Kron | first5=D. G. | last6=Lander | first6=B. | last7=Manning | first7=E. | last8=Prothero | first8=D. | author8-link=Donald Prothero | last9=Stevens | first9=M. S. | last10=Stucky | first10=R. K. | last11=Webb | first11=S. D. | last12=Wright | first12=D. B. | editor1-last=Janis | editor1-first=C. M. | editor2-last=Scott | editor2-first=K. M. | editor3-last=Jacobs | editor3-first=L. L. | title=Evolution of Tertiary Mammals of North America | url=https://archive.org/details/evolutiontertiar00jani_419 | url-access=limited | date=1998 | publisher=Cambridge University Press | location=Cambridge, UK | isbn=978-0-521-35519-3 | pages=[https://archive.org/details/evolutiontertiar00jani_419/page/n175 337]–74 | edition=1st | chapter=Artiodactyla}}</ref><ref name="Heffelfinger">{{cite book | last1=Heffelfinger | first1=J. | title=Deer of the Southwest : A Complete Guide to the Natural History, Biology, and Management of Southwestern Mule Deer and White-tailed Deer | date=2006 | publisher=Texas A & M University Press | location=Texas, US | isbn=978-1-58544-515-8 | pages=1–57 | edition=1st |url=https://books.google.com/books?id=AJnpJWzamN4C}}</ref> Analysis of a nearly complete skeleton of ''Diacodexis'' discovered in 1982 gave rise to speculation that this ancestor could be closer to the non-ruminants than the ruminants.<ref>{{cite journal | last1=Rose | first1=K. D. | title=Skeleton of ''Diacodexis'', oldest known artiodactyl | journal=[[Science (journal)|Science]] | date=1982 | volume=216 | issue=4546 | pages=621–3 | doi=10.1126/science.216.4546.621 | pmid=17783306 | jstor=1687682| bibcode=1982Sci...216..621R | s2cid=13157519 }}</ref> ''[[Andromeryx]]'' is another prominent prehistoric ruminant, but appears to be closer to the [[Chevrotain|tragulids]].<ref>{{cite book | editor1-last=Eldredge | editor1-first=N. | editor2-last=Stanley | editor2-first=S. M. | title=Living Fossils | date=1984 | publisher=Springer | location=New York, US | isbn=978-1-4613-8271-3}}</ref>