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Your Permian cousins
July 20, 2010 5:23 AM   Subscribe

Today mammals are the only surviving members of the Synapsids, but several hundred million years ago, they had company. Meet the dicynodonts: beaked, sabre-toothed herbivores that look like nothing you've seen before.

Non-mammalian synapsids like the dicynodonts, and their relatives the gorgonopsids, were traditionally classed as "mammal-like reptiles", but they aren't truly reptiles, either. We still don't know a huge amount about how mammal-like they were; they may or may not have been warm-blooded, may or may not have laid eggs, and may or may not have cared for their young. Most of them died out with the rise of the dinosaurs. A recent discovery of a fossil in Australia suggests that at least one branch of the dicynodonts survived to live alongside the dinosaurs, 110 million years after the rest of the family were extinct - but some remain sceptical.
posted by Catseye (21 comments total) 17 users marked this as a favorite

 
Hmm.
So what did they eat with? Something that was unique among the synapsids: they had a beak. Instead of dicynodont, perhaps they ought to have been called psittacostiosaurs (bird mouth reptiles/lizards) or psittacoaazosaurs (pretty much the same thing) rather than refer to the tusks. Their jaws were something extraordinary though. They had a shearing action that, as far as I have found to date, is unique among the synapsids. To show it, I am going to swipe a picture from what is probably one of the best websites on the therapsids online:
And then a 404. Anyone got a working link to that?
posted by pracowity at 5:42 AM on July 20, 2010


And then a 404. Anyone got a working link to that?
Here's the Internet Archive's copy, via the Wayback Machine.
posted by snuffleupagus at 5:51 AM on July 20, 2010


Thank you, my Quaternary cousin.
posted by pracowity at 6:03 AM on July 20, 2010


I found the Wikipedia page more useful and better-written than the front-page link. Not that you could have used it instead; people would have complained.
posted by Kirth Gerson at 6:08 AM on July 20, 2010


Unfortunately, snuffleupagus' link doesn't actually contain the images in question: The Internet Archive has the text but not the images.

Through a little poking around, I've found another copy of the original source website which itself long gone but where the Internet Archive has actually archived the images as well as the text:

Page here.
posted by pharm at 6:08 AM on July 20, 2010


I scanned that whole hard-to-read block of white-on-black text and didn't see the answer to this: Why would an herbivore have fangs? They look poky, unlike an elephant's tusks. Is it to hold a tree trunk (or whatever) steady while the jaw slices it?
posted by DU at 6:08 AM on July 20, 2010


Oh, boy.

I am having a case of the good old Bader-Meinhof spookies in which the Permian is appearing everywhere.
posted by millipede at 6:20 AM on July 20, 2010


Why would an herbivore have fangs?

Look at the link that pharm graciously provided, with images of the "jaw mill" -- the tusks could have served as a fulcrum point to scrape off vegetation during the backwards motion of the lower jaw.

But paleontological behavior is a tough nut, I think.
posted by Made of Star Stuff at 7:29 AM on July 20, 2010 [2 favorites]


Oh, synap(sid)!

I am having a case of the good old Ba(a)der-Meinhof spookies in which the Permian is appearing everywhere.

Mine is with the ghosts of evolution (previously) and the might-have-beens that follow. So of course I focus on this part:
Remarkably, there was a singular fossil found in Australia from the early Cretaceous from an unknown dicynodont. It came from a region that contained exclusively Cretaceous strata and thus precluded this being a reworked fossil. This is a good example of a Lazarus Taxon or Ghost Lineage.
I love counterfactual paleohistory, and the suggestion of a near-miss rival line of big critters that follows is pretty awesome.
posted by norm at 7:55 AM on July 20, 2010


It's really a shame our popular culture focuses so intently on a relatively small number of overused extinct species - your T Rexes, your Triceratops, your Smilodon. Maybe, if it's kind of exotic, you'll get an image of an ancient sea floor with a trilobite. But life on this planet has a really weird past, and I love these reminders of how much crazy cool stuff there is floating around back there. Whale-eating whales! Tusked beaked sorta-mammals! Never mind the present-day crazy-critters like the poor doomed male angler fish whose sorry tale we had here recently. Life is awesome.
posted by Tomorrowful at 8:10 AM on July 20, 2010


Meet the dicynodonts: beaked, sabre-toothed herbivores that look like nothing you've seen before.

Seen it.
posted by nathancaswell at 8:11 AM on July 20, 2010


Why would an herbivore have fangs

Ask a hippopotamus. Lots of creatures have pointy structures that are useful in defense, mating combat, forage, or some combination of the three.
posted by kuujjuarapik at 8:19 AM on July 20, 2010


There's also a small species of deer that has tusks. Forget its name just now.
posted by Guy_Inamonkeysuit at 8:34 AM on July 20, 2010


Boy, if there's an intelligent designer running around, He certainly went through a lot of rough drafts.
posted by jenkinsEar at 8:37 AM on July 20, 2010


There's also a small species of deer that has tusks. Forget its name just now

Musk deer.
posted by norm at 8:40 AM on July 20, 2010


I want.
posted by elder18 at 8:53 AM on July 20, 2010


There's also a small species of deer that has tusks. Forget its name just now

This brought back memories of a biology guest lecture I attended at a research station in about 1992. The guest team had just returned from a cataloging and exploration expedition in western China, and they had amazing pictures of all these weird animals I had never even heard of before, including these funky little deer with fang-like tusks. It blew my mind. The only downside was that due to the techniques of the Chinese partner team, most of the pictures were of dead or bear-trapped specimens.

"Aww what a cute little deer ... ohhh ... ack ... didja have to ... sheesh."
posted by freecellwizard at 10:54 AM on July 20, 2010


It's really a shame our popular culture focuses so intently on a relatively small number of overused extinct species

I totally agree. My daughter's gone dino-crazy (especially for raptors, which fills me with no end of delight; deinonychus FTW!) and that's relit my childhood passion for prehistoric beasties, but I find myself drawn more and more to the synapsids the more I read.

The models I was brought up on have continued to evolve; a new posture for T. rex, feathers for the raptor species, oviraptor not so much eating protoceratops eggs as brooding her own.

The Permian has been given the same re-evaluation, but not nearly the same public mind-share. I guess that giant lizards are just too sexy to share the limelight.
posted by lekvar at 4:57 PM on July 20, 2010


Heh. The author of that blog is getting so many hits that he thinks he's under a DDOS. Somebody explained to him that he's been linked by Metafilter.
posted by Joe in Australia at 7:47 PM on July 20, 2010


Why would an herbivore have fangs

Ask a hippopotamus.


Actually, those aren't considered fangs by the scientific community, but rather exist in their own unique dental category. The technical name for what a hippo has is Bloodrazor murder-sabers.
posted by Uppity Pigeon #2 at 10:12 PM on July 20, 2010


While neither fast nor agile, powerful legs would have made it a good long distance walker.

The key to their extinction -- they were damned with faint praise.
posted by eddydamascene at 11:37 PM on July 20, 2010 [3 favorites]


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