Fossil Friday – camel metacarpal

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For Fossil Friday, we have the hand bone (front foot bone) of the western camel, Camelops hesternus, seen here in anterior view (the bottom is to the left). It was collected about a mile from where the museum is now located, and was associated with several other camel bones.

Like many other members of the Artiodactyla, the “hand bone” (or metapodial) in camels is actually two bones fused together, the 3rd and 4th metacarpals. Even though the two bones are fused together for most of their length, there is still a visible groove indicating where they’re fused, and at the distal end the bones are still separated. At the distal end each metacarpal articulates with a separate finger; the articulation is more clearly visible in the posterior view of the same bone, with the articulation on the left:

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These correspond to the middle and ring fingers in humans. The foot has a similar arrangement. Since most artiodactyls have this two-finger, two-toe arrangement they are sometimes called the “even-toed ungulates”.

It’s easy to forget how big camels are. Camelops hesternus was roughly the size of modern camels, and they are massive animals. This metapodial is close to 35 cm (over a foot) long. Here’s what a whole skeleton looks like, from the exhibit at the George C. Page Museum:

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Even though Camelops hesternus was comparable in size to a modern camel, it was actually more closely related to the llamas and vicuñas from South America, and was the largest member of that group. Camelops went extinct shortly after the end of the last Ice Age.

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