When turtles lost their teeth

When animals lose something,
be it a tail, finger, limbs, eyes or teeth, usually a vestige is left behind.

When turtles lost their ancestral teeth,
they should have left empty alveoli along their jaw rims. And the place to look for empty alveoli in turtles is in the most primitive turtle in the large reptile tree, the late-surviving Niolamia (Fig. 1), one of the great horned meiolaniid turtles.

Figure 1. Palate of the basal turtle Niolamia with arrows pointing to pinprick alveoli lacking teeth.

Figure 1. Palate of the basal turtle Niolamia with arrows pointing to pinprick alveoli lacking teeth.

Tiny pinpricks
along the maxilla (Fig. 1) seem to show where tiny teeth once erupted in Niolamia.

Earlier we looked at similar alveoli in the jaw tips of a gray whale where desmostylian tusks once emerged.

3 thoughts on “When turtles lost their teeth

  1. When turtles lost their ancestral teeth,
    they should have left empty alveoli along their jaw rims

    That makes no sense at all. Alveoli aren’t separately encoded in the genome (and then inherited for another 150 million years!!!), they’re caused by the presence of tooth roots. What’s inherited is the reaction of bone to the presence of a tooth root.

    This goes so far that, when humans lose permanent teeth, the alveoli fill in with bone.

    You’re probably looking at vascular foramina for the beak, but the picture is so grainy I can’t tell for sure what these black dots are.

  2. Earlier we looked at similar alveoli in the jaw tips of a gray whale where desmostylian tusks once emerged.

    That’s not in that post. Where is it?

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.