Quadruped question

#1

I have a question,

is there a defining word between a quadruped with hoofs and a quadruped with toes?

Thanks,

Kasper

#2

Sure… lets go through the gradations though. Those with toes, but heels in contact with the ground (like humans) are plantigrade. You then get some creatures who have a raised heel (and by extension ankle), but who have heavy padding beneath the heel which still makes ground contact (like elephants) who are semi-plantigrade. Then you get those creatures who’s heel and ankle are fully elevated (to an extent you can say they dont even have a “heel” in the way we think of it), with toes spread flat on the ground… (things like cats, dogs, etc)… these are digitigrade. Finally you get creatures who effectively walk on tiptoes, where the toenail has become a thickened contact surface, a hoof (like horses goats and so on). These are unguligrade.

Main difference is in the joint count… plantigrade and digitigrade creatures have 3 active joints in the main limb… hip, knee and ankle. Ungulates have a fourth (which is actually a toe joint that has become part of the main limb).