In advance of a looming non-dissertation publication (on what else but metoposaurids), the next three weeks will be dedicated to my favourite temnospondyls. This week will introduce metoposaurids in all their slimy, flat-headed glory; next week will highlight some of the latest research on this group by people other than me (there's a lot!); and the last week in May will feature a nice story on how I ended up obsessed with this peculiar group of largely ignored temnospondyls (it is actually a pretty good story if you ask me)! I'm also coining the hashtag #MetoposauridMay (to go with the occasionally used #MetoposauridMonday) to give some veneer of having a topical theme for this month.
Distinguishing features The most prominent feature is the forward positioned eyes (orbits), although this is only particularly useful among Mesozoic temnospondyls; some Paleozoic clades like dvinosaurs also have eyes that are relatively far forward. Most other features that are considered diagnostic (e.g., broad, flat cultriform process on the palate) are pretty uncommon, but they aren't unique to metoposaurids, and it's more that the combination of these various features is unique to these animals. Among other coeval (living at the same time) temnospondyls, the position of the eyes and a few other features make them pretty easy to differentiate. The nature of the food Metoposaurids were big enough to fit a lot of things in their mouths. But they were pretty heavy-set animals and were probably not particularly agile swimmers in the mid-water column (compared to something that can do underwater acrobatics like seal lions). Their flat skulls, with the eyes on top, and relatively simple, conical teeth suggest that they primarily ate fish, rather than trying to crush shelled animals or slice through flesh. They definitely were not filter feeding mud as was once suggested (Branson & Mehl, 1929). Of course, it's worth pointing out that we have never found a half-digested fish inside of a metoposaurid, and although there are often coprolites (fossil poo) associated with metoposaurids that have fish scales, direct evidence of fishy preferences is unknown. A day in the life Of course I have no idea what metoposaurids did with their average day. I imagine it involved a lot of sitting around at the bottom of a lake or pond and then having to stretch to go up for air. Maybe go sit in the shallows (but not on the beach) to warm up a little bit. Eat a coelacanth here and there. Step on your friend who took your favourite muddy ditch while you were gone. Sit on your friend when it won't budge. It's the simple pleasures, really. Refs
David Marjanović
5/16/2019 02:06:03 pm
"originally described as a subspecies of M. diagnosticus (maybe it should have stayed that way to be honest)"
Martin
5/21/2019 11:05:20 pm
Damn, that's harsh my dude. I'm just kidding. It's stone cold science. People are usually cushion the paleo-criticism with a compliment on Deviantart. I'm just joshing you. in case I came off as mean that's not my intention.
David Marjanović
5/27/2019 01:38:01 pm
Ah, sorry for the culture shock – that's not a feature of Deviantart, it's an American thing to never criticize without adding explicit praise. :-) It should go without saying that I like the rest of this post very much!
Martin Fernandez
5/21/2019 11:08:49 pm
Very cool and informative blog post. I didn't know metoposaurids were so widespread. I thought they were just known from Germany and USA. Comments are closed.
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About the blogA blog on all things temnospondyl written by someone who spends too much time thinking about them. Covers all aspects of temnospondyl paleobiology and ongoing research (not just mine). Categories
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