İzmir Name Meaning:  Daphoenus Tooth

http://davidbjelland.com/tube.com/embed/q8PNWA1noFo Geologic Era:  Late Oligocene to Miocene

Lecce Location Found:  Nebraska

Elizabeth City Size:  Small (1 meter in length)

Estimated Range:  Most of United States

Extinction Date:  Middle of Miocene (around 16 million years ago)

Daphoenodon was a small amphycyonid carnivore, distantly related to larger animals such as Amphicyon.  Our tooth is most likely a canine tooth, meant for piercing and holding prey.  A close examination reveals that our tooth is hollow, with only the enamel being preserved.  It also appears to have been split in half at some point, and glued back together.  Most of the tooth is present, with only a section of the root (and the interior of the tooth) being missing.  There are several species of Daphoenodon described in the fossil record, but I am unsure as to which one our tooth belongs to.  I will use Daphoenodon superbus as my reference animal.  D. superbus was found in the same location and same geological strata as our tooth, so it would be a reasonable guess.  

Daphoenodon would probably have fit into the same ecological niche as modern foxes, going after smaller prey items such as rodents to small lizards.  It would have left the larger prey to its larger, more powerful cousins.  While small, Daphoenodon was still a beardog.  Most beardogs had very powerful muscle attachments for their jaws, meaning they could deliver a very strong bite for an animal of their size.  While perhaps not “bone crushing” like some of their larger cousins, Daphoenodon could have easily crushed smaller prey items like rodents and birds.  There is also some evidence that Daphoenodon and some of its relatives dug burrows.  Many modern canids engage in this behavior, whether to have and care for pups or for shelter from the elements.  

A close look at Daphoenodon’s feet reveal that it walked in a plantigrade, or flat-footed manner.  This is on contrast to modern canines, which are digitigrade walkers.  In this respect, Amphicyonids like Daphoenodon would have moved more like modern bears than canines.  While plantigrade stances give an advantage in terms of stability and weight bearing, it comes at a cost of speed.  This stance effectively shortens the leg, and makes higher speeds difficult.  This possibly meant that the prey animals of the time were much slower than later ones, as the Amphicyonids were a very successful group of animals.  It was the development of faster prey and changing landscape that led to the extinction of this once diverse group.  Amphicyonids leave no modern descendants, though they are probably distant cousins of modern bears and canines.  

Image Credits:

Skeleton:  “Large osborn daphaenus” by Peterson. – http://www.copyrightexpired.com/earlyimage/bones/display_osborn_daphaenus.htm. Licensed under Public Domain via Commons – https://commons.wikimedia.org/wiki/File:Large_osborn_daphaenus.jpg#/media/File:Large_osborn_daphaenus.jpg

Life Restoration:  “Daphoenus” by Robert Bruce Horsfall – http://www.archive.org/details/ahistorylandmam00scotgoog. Licensed under Public Domain via Commons – https://commons.wikimedia.org/wiki/File:Daphoenus.jpg#/media/File:Daphoenus.jpg