Conodonts: 520 Million Years Long in the Tooth

Decent conodont fossils are frustratingly rare. Sure, their 'teeth' are so well known they're used as index fossils, id est, the distributions of particular types are used to gauge the age of the rocks in which they're found. Lacking the hard, bony skeletons of 'vertebrates proper', they don't leave so much to fossilise; ergo, only a handful of not-teeth-fossils are known. It's hardly surprising, then, that the arrangement of the hard elements within the head isn't fully understood. The animals are generally pretty small, ranging from 10mm to 400mm, and the teeth are only rarely found associated with the animal which used them. It's not even clear from the remains themselves how they were used, with a variety of feeding methods proposed, including filtration, crushing and actively grabbing hold of small prey. It's not hard to imagine conodonts as analogous to extant eels, and eel-like lampreys and hagfish - after all, they share a broadly similar form - but the feeding methods employed by those animals are disparate to say the least.

Given the poor preservation of the soft tissue elements of conodonts, many reconstructions are understandably pretty basic represented by little more than line art (and there's nothing wrong with that). However, Davide Bonadonna has put together this incredible image, which is probably the nearest anyone is going to get to a face-to-face encounter with our fishy (fishesque? fishish?) friend. Mercilessly terrifying, mercifully small.

Rocking the 'someone stepped on my tail' look: Clydagnathus. (Copyright © Davide Bonadonna.)

So Davide's pop-eyed conodont inspired something a little less scientific from me, in the form of this Alien3-Clydagnathus mash-up, and is available on products at my Redbubble store, here. And if you prefer something a little more scientific, you can buy Jaime Headden's instead.

The conodont Clydagnathus, which, were it alive today, would gestate in your chest and eventually smash through your ribcage. Why? Because pop culture. (Copyright © 2016 Gareth Monger)

Big thanks to Davide Bonadonna for allowing the use of his work in this glorified advert. If you're unfamiliar with his incredible work, correct that immediately!