Excerpts from Jim Conrad's
Naturalist Newsletter

from the May 9, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO; limestone bedrock, elevation ~39m (~128ft), ~N18.52°, ~W95.15°
MYSTERY SKULL

When a friend told me that the bones of a chicken back were an iguana skull, and I believed it, another friend quipped that as a skull expert I was a good vegetarian. Therefore, when this week a skull turned up near where that chicken back had been unearthed, I grew very circumspect. Can you ID the skull shown below?

rabbit skull

This time a friend told me that it was certainly the skull of a Tepescuintle, a piglike, large rodent the Maya used to eat a great deal of before Tepescuintles got scarce. The Tepescuintle skull I found on the Internet matched my discovery, so I started feeling confident.

However, just before my friend had come along saying it was a Tepescuintle skull, I'd shipped the picture to an address at "Skulls Unlimited International, Inc." where someone offered to identify skull pictures sent to them. Apparently that organization is associated with the Museum of Osteology in Oklahoma City. (http://www.museumofosteology.org)

The next day, Joey Williams, Director of Education there, replied:

Rabbit.

I sent him the Internet address of the Tepescuintle skull and he replied that that was a misidentified rabbit skull. He even returned my own picture highlighted and labeled to show what made the rabbit skull a rabbit skull, and you can see that below:

rabbit skull showing rostral fenestration and two sets of incisors

He writes:

Rabbit and hare skulls (Lagomorphs) are easily distinguished by two skull characteristics:
  1. Rostral fenestration... which is all the holes in the side of the animal's "snout" or rostrum, and
  2. A double set of upper incisor teeth.

From this exercise I deduce three facts: 1) I'm still not much of a skull identifier; 2) Don't trust everything you find on the Internet, and; 3) That Museum of Osteology web address is worth holding on to.