I'm sure you'll agree that there have been way too many dinosaurs on Tet Zoo over the past few weeks. Let's balance things out by showing a cute little rodent. Your challenge: to identify it to species and - if at all possible - to say something quite interesting about the animal, or about the group to which it belongs. Good luck, and don't stop until we get to 100 comments...
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Thryonomys swinderianus (Cane rat)?
Largest African rodent.
Double grooved upper incisors.
While I'm sure it must be something more exotic it looks like a groundhog to me.
*Marmotagorgon*, a highly derived gorgonopsian strongly convergent on ground squirrels.
Possibly a big fat prairie dog.
Looks suspiciously like a prairie dog. Though a juvenile Rodent of Unusual Size is also a possibility.
The special feature must be that it is a descendant of a small group of burrowing pterosaurs.
Hate to disagree, The only reason I come here is for the excellent dinosaur coverage. There is literally none better on the web. All good things must come to the end.
that is a juvenile plumpus contentus, my basenji caught one eating figs in our garden yesterday. The male adult can become as large as a garbage can.
Thanks for posting this, it is really nice to have a non-dinosaur back here. I mean, unless you keep in mind that some led to birds, non-avian dinosaurs never seem to have made the transition to being aquatic.... at least Thryonomys can claim a connection to an aquatic hystricognath, Hydrochoerus.
I don't mean to be so single-minded, but it is curious that primates and non-avian dinos are some of the only groups to not have aquatic members. Even Mesozoic mammals have at least one aquatic example in Castorocauda.
Thanks!
Well, I haven't found anything to disconfirm my first guess: prairie dog (Cynomys) (Heh - that apparently really does mean "dog mouse".)
Interesting prairie dog fact: Some researchers, led by Northern Arizona University professor Con Slobodchikoff, think that prairie dogs have a fairly sophisticated pseudo-language, although (wait for it...) others dispute this claim.
Here and here.
âCute, furry, has claws, [and] bitesâ?
An amalgamation of SciBloggers.
Richardson's Ground Squirrel ?
White-Tailed Prairie Dog, Cynomys leucurus. The prairie dog of least concern?
Looks like a Prairie Dog. I am probably wrong, some of us have to make due with a Georgia high school level of education.
Cynomys leucurus is my vote too.
This game is so much harder when you can't see the skull, especially in rodents. All those little buggers look so much the same!
My guess it's Cynomis sp. Hm, a prairie dog?
There is something particular about their sight if I'm not mistaken. And yes, they look very sophisticated eating a dandelion.
Is it Petromus?
Appears to be an American Pika
Certainly a ground-squirrelish sciurid.
Are they interesting, somehow?
Hibernation, intereting for sure.
"Appears to be an American Pika" - don't they have big ears?
Pikas aren't rodents.
(And that's all I can contribute. Temnospondyls!)
Too many dinosaurs? Ain't no such thing!
That's the cutest, fuzziest marmot I've ever seen. But that's as specific as I can get.
You know, I'd agree that it's a ground squirrel of some sort, but it's certainly the fattest one I've ever seen. Is it just sitting at a strange angle or something?
True, Pikas were once considered a sub-order of Rodentia but along with Rabbits and Hares are in the order Lagomorpha.
Definitely a terrestrial sciurid. I don't really know which species, but like Rosel, I'm guessing it's a Richardson's ground squirrel Spermophilus richardsonii.
That's my fat hamster. I call him Fatty.
interesting fact: he can eat his own body weight in dog biscuits. And he loves the birds come first hypothesis.
no, the hamster's name is Fatty James.
Could it be a Gundi?
My first instinct was Richardson's ground squirrel as well... I don't know anything interesting about it except that I know there are a few individuals in captivity in the UK, especially at Longleat Safari Park. I hung around the exhibit for ages waiting to see them, but alas, they were probably underground, sleeping.
Oh I've just thought of something interesting about the genus Spermophilus (at least the subgenus Citellus), aren't they notorious for having been the instigators of the Black Death in eastern Europe/central Asia? Or is that marmots?
My guess is the European Ground Squirrel (Spermophilus citellus)..though the pic I found of one is just a little off, so it might be a related species instead.
In guides to the mammals of Europe, the ground squirrels always stood out to me because of their distinctive names. For anglophones, they aren't very idiosyncratic but for Dutch speakers like myself...'soeslik' (Spermophilus) , 'siesel', 'alpenmarmot' and 'bobakmarmot' have a nice ring to them.
Non conclusive identification. I need to do more research at CuteOverload.com.
It's a Richardson's Ground Squirrel, Spermophilus richarsonii. I don't know anything too interesting about it except that the Saskatchewan Wildlife Federation sponsored a hideous, barbaric "gopher derby". Cash prizes were given to the a..hole who killed the most of them. Oh, and they're adorable.
Brian Beatty: Non avian dinosaurs DID produce semi-aquatic forms. The shed teeth of Ceratosaurus nasicornis are often found among the remains of turtles, crocodiles, and lungfish (and some terrestrial dinosaur remains too, of course). I know not everyone agrees with Bakker's conclusion that the reptile was semi-aquatic, but why else would it have evolved a deep, powerful, crocodilian-like tail, with nearly vertical vertebral spines? Then, of course, there's Mujungasaurus crenatissimus. With its incredibly shortened legs, very low center of gravity, and huge, powerful, and again crocodilian-like tail, it must have been even more at home in the water than was Ceratosaurus. I would like to know of one (just one) reptile that has a tail like this (very flexible, long, with very deep chevrons and tall, vertical vertebral spines) and isn't aquatic to a decent degree.
BTW, I really hate to disagree, but I can NEVER have enough dinosaurs. Never. Ever.
It's a marmot; marmots communicate using whistles.
Awluk haucuteus ?
Speaking of which, anyone got any ideas how we can blackmail BBC into making a Waddling with Temnospondyls?
Could it be a Rock Dassie (Procavia capensis)?
Wiki tells us that Hyraxes are widely stated to be the closest living relatives of elephants but I suppose their most interesting characteristic is that Rock Hyraxes produce large quantities of hyraceum (sticky mass of dung and urine) that has been employed by people in the treatment of several medical disorders, including epilepsy and convulsions.
Hoot man! Caerbannog!
http://en.wikipedia.org/wiki/Rabbit_of_Caerbannog
It is a Fluffyaplumpasaurus adorabilis. Fluffyaplumpasaurus is a small maniraptoran theropod dinosaur that is convergent with ground squirrels. It has secondarily reverted to a protofeather covering that resembles fur. It has evolved cheeks like those of ornithischians, and a tiny mouth. The tiny mouth makes the theropod look harmless, when in fact it is a vicious beast that uses sharp claws to punture the heads of its prey. It then uses the tiny mouth to suck out the brain. Fluffyaplumpasaurus is the only theropod whose diet consits only of brain matter. The species name, adorabilis, refers to its deseptively adorable appearance.
Nasty Big Sharp Point Teeth! Run Away!!!!
C'mon, everybody! You heard the man! Don't stop until we have 100 comments! Let's keep it moving!
How long is the tail? What continent? Is it rare or common
Actually, yes, it could be a (very fat) marmot. But comment 31 sounds very authoritative. :-)
Aren't marmots exclusively montane in Europe?
That's not conclusive... especially it doesn't mean it swam...
(Not that it matters, but just about nobody does.)
Is its tail really that special? Doesn't it taper at the tip, unlike a crocodile's?
Often (though not always), vertebrates that are tail-propelled swimmers have neural and haemal spines that are strongly inclined backwards.
Doesn't it just look that way because the legs are so short? Keep in mind that tyrannosaurs and other coelurosaurs are not a good comparison.
Its head is built for attacking sauropods, and it lived in a pretty dry area.
How is "reptile" relevant here, actually?
Finally, why would any theropods converge on crocodiles when crocodiles are abundant?
...and as such, they're not rodents. When I first saw the picture, I thought "hyrax" too, but the text says it's a rodent.
BTW, the hyraxes are the closest living relatives of the sea cows. LINE insertions can't be argued with.
The Bobak marmot (Marmota bobak) is native to the steppes of eastern Europe and central Asia.
Could it be a Bank Vole?
why, that is a Havanese Burrowing Dirt Hamster, of course.
Hornless Jackalope, native to the North American Great Plains states (Kansas, Nebraska, Dakotas, etc.). Most people are familiar only with the more common varieties, the ones with antlers.
It appears to have a collar, the brown sumner coat of the Siberian collared lemming.
David Marjanovic: I should have been a bit more clear. By "aquatic", I didn't mean they spent their whole lives in the water. I'm certainly not saying that they were fully aquatic like most modern crocodilians. I simply meant that they (may have) had aquatic habits.
"That's not conclusive... especially it doesn't mean it swam.. "
You're right there. But all theropods COULD swim very well if they needed too. Big ratites can. That the teeth are present in the remains of aquatic vertebrates *suggests* that it would have swam after them (although it certainly could have walked into the shallows and picked them up as well).
"Is the tail really that special? Doesn't it taper at the tip, unlike a crocodile's?"
The tail is special in that it's unusually deep, and it's more flexible (from side to side)than is normal, even for basal theropods. It does, indeed, taper at the tip, unlike a crocodile's, but like another extant reptile with aquatic habits: the Nile Monitor.
"Often (though not always), vertebrates that are tail-propelled swimmers have neural and haemal spines that are strongly inclined backwards."
Really?! Example please?
Also, all that this means is that you need not have vertical neural spines to be a tail-sculler. Is there a reptile with tall, vertical neural spines on the tail that is fully terrestrial?
"Doesn't it just look that way because the legs are so short?"
Yes, but WHY are the legs so short? Other abelisaurs (perhaps significantly, those without crocodilian-like tails) have very long legs.
"Keep in mind that tyrannosaurs and other coelurosaurs are not a good comparison".
"Tyrannosaur" never entered my mind. I would never compare an abelisaur to a tyrannosaur.
"The head is built for attacking sauropods, and it lived in a pretty dry area."
Besides being very heavy and powerful, how is the head of Majungasaurus (Mujungasaurus was a typo) built specifically for attacking sauropods? Couldn't the head also be heavy to aid in desent, like a crocodile's? And the Serengetti is also a pretty dry area, but there are water holes that can hold, for example, many giant crocs.
"How is 'reptile' revelent here, actually?"
Dinosaurs are (phylogenetically speaking) reptiles, are they not?
"Finally, why would any theropods converge on crocodiles when crocodiles are aboundant?"
Why would avian dinosaurs (birds) evolve the ability to fly when pterosaurs are aboundant?
Remember that I will always appreciate ANY responces to my comments, so thanks!
"I don't mean to be so single-minded, but it is curious that primates and non-avian dinos are some of the only groups to not have aquatic members."
I think you could almost classify some groups of humans as marine mammals. I'm thinking of groups like the Inuit, who live almost entirely on marine foods and spend quite a lot of time on the water. If they were the only humans, then...
Anyway, as for the varmit, I'm going to say it's a woodchuck preparing to chuck that wood it's sitting on.
BTW, don't the tails of phytosaurs, like Rutiodon, taper at the tip as well?
It really does look the most like a Richardson's Ground Squirrel to me, Spermophilus richardsonii, Going entirely off of pictures and growng up in the Rockies of Colorado USA, though.
Were it not for the "rodent" label (ok, and the claws), I'd have said Rock Hyrax, just because it is so cool that something similar to your pic is a close relative of an elephant.
That little guy is still a Spurmophilus richardsonii, albeit the fluffiest, chubbiest, most delectably adorable one I've ever seen.
Waddayaknow, I came up a few (possibly)interesting things abut the cutie. For starters, it's known by a TON of common names, suh as "picketpin", "flickertail", "tawny American marmot", "yellow gopher", and simply "gopher". They are often confused with prairie dogs, and they also appear to be popular as pets. I think the pic could certainly expain that last part..
An argument could be made for the Groundhog, a/k/a the Woodchuck, Marmota Monax. Consider this picture (Wikipedia).
A Dwarf Giant Space Hamster?
I say Richardson's Ground Squirrel. I've been TAing geology field camp here in SW Montana, and they look just like the critter in the photograph.
Today, I watched a western rattlesnake spend 40 minutes swallowing one of these guys. Pictures (lots of them) will be up on "The Coastal Paleontologist" 'soon' (either tommorrow, or in a week when the final mapping project is done).
But ya, I think Michael and Brett are right - Spermophilus richardsonii.
Thanks, Boesse!
How much wood would a woodchuck chuck if a woodchuck could chuck wood?
(rapidly repeat comment 42 times!)
How much wood would a woodchuck chuck if a woodchuck could chuck wood? How much wood would a whhodchuck chuck if a woodchuck could chuck wood? How much wood would a woodchuck chuck if a woodchuck could chuck wood? How much wood would a woodchuck chuck if a woodchuck could chuck wood? How much wood would a woodchuck chuck if a woodchuck could chuck wood? How much.. Will that do, DDeden?
I'm not sure, but I think it might be a parky squirrel, S. parryii. They are called parky squirrels locally because their tiny pelts can be pieced together into elaborate and beautiful parkas. They were most likely introduced to the Kodiak Archipelago hundreds of years ago while hibernating, wrapped up securely in the bow of an umiak (leather open boat with a sail), because their pelts are so valuable. They hibernate so deeply that you can pass one around an entire classroom full of people and it won't stir--just be sure to put it back in the cooler in its terrarium after the demo, so it wakes up on the usual date.
To me it does not look like any kind of squirrel. Too fat, no tail. I suggest it is some species of cavy, a large family (Caviidae) of South American rodents. The best known member of the family is the domestic guinea pig (Cavia porcellus), whose wild ancestor is unknown. A possibly interesting fact: the guinea pig is the only food mammal ever domesticated in the New World (there are several domestic birds). It is widely eaten in South America and there are attempts to market its meat in Europe and North America.
More dinosaurs, please.
Looks like a prairie-dog to me but why the little rascal ois sitting on a look beats me.
Maybe he thinks he's King Louis of France.
Or another high ranking frog-eater.
Highly unusual for a prairie-dog who are -on the whole- more inclinded co communism.
It makes you wonder whether it could be a disguised pterodactylus of some sort after all having a laugh at the rest of us.
A highly clever masquerade I must say.
Doyne Dawson
There is some debat going on whether the prehistoric Amerindians of the Caribbean islands domesticated the hutia.
(In this case Isolobodon Portoricensis)
If this is a Spermophilus, as some have suggested, then surely the remarkable thing about it is how obscene its generic name looks.
HOLY CRAP: Tet Zoo made it into the top 7 finalists for the 3 Quarks Daily 2009 science award. I am shocked. Thanks to all who voted, and fingers crossed :)
Its a Spermophilus groud squirrel - one of the north American species (the European ones are quite differently coloured). The cinnamon/buff-tan marking on the head narrows it down, and over all it looks most like Richardson's or Uinta - since Uinta ground squirrel looks somewhat darker in the pictures I have, I think its probably Richardson's ground squirrel.
It's not only the fact that the article said 'rodent' that rules a hyrax out - look at the feet.
Damn, I'm late to the party... I was thinking prairie dog at first, but yes, Richardson's ground squirrel appears to be a good match.
Doyne Dawson: Many of the ground squirrels have a rather insignificant tail, compared to their arboreal cousins.
And what about the llama and alpaca? If I'm not wrong, they are also utilised for their meat.
I second (third? fourth?) the Spermophilus ground squirrel identification, though I don't know enough about them to identify it to species. Interestingly, I wrote a paper in my herpetology class critiquing a study about SSA (Snake scent application) in Spermophilus ground squirrels. The little guys pick up shed snake skins, usually from rattlesnakes, chew them, and then rub the chewed bits on parts of their bodies. The authors of the paper thought it was probably meant to deter rattlesnakes, because the snakes might be scared of the scent of another snake in their territory. Cool stuff!
Guinea pig (noones gone for it and theres a 1 in a million chance in right of darren will gat a bonk to the head and forget something for once, and think it is a guinea pig) - a hamster is stunted dwarf guinea pig.
I admit to hoping it would turn out to be a hyrax, but Darren would never have slipped up and called it a rodent. Anyway the claws are all wrong.
"How does an elephant hide in a strawberry patch?" "It paints its toenails red."
Sorry, but to me the little dude looks nothing like a hyrax. The snout is wrong, the ears are wrong, the claws are wrong, and Darren said that it's a rodent. I just can't see how it could be anything other than a Richardson's ground squirrel. Doyne Dawson: It looks ABSOLUTLEY NOTHING like a cavy! Google Image "cavy" and see what I mean. It's fat, but I've seen some pretty fat squirrels before. The lack of a tail doesn't mean anything -its probably curled around the other side of the critter. Note that we can't see the hind legs either. It's still Spermophilus richardsonii.
Fine, if it's a Richardson's ground squirrel, what are the interesting things about them?
I like how you put no-clues-here in the source file for the image. Very funny!
I'm jumping on the Richardson's Ground Squirrel Bandwagon. One neat thing about it [from Wikipedia] is that some adults begin hibernation in July. After emerging in March, that would mean that they spend about 2/3 of the year in a dormant state. That's one way to avoid all them predators.
Either that or the Giant Tailless Lap Gerbil. Good company for watching TV on cold winter nights. If you don't have a blanket. And you have leather gloves. Darren says they bite.
Nathan Myers: I've already posted a few interesting things about them (all I could come up with, anyway). You can find them 18 comments above my last one.
If it`s a Vole, it could be one of 121 species, a Lemming one of 17, take your pick.
Whistle pig.
Mountain Beaver.
If Rock Hyrax are excluded (my bad) then it could be the Dassie Rat (Petromus Typicus) because it just has to be a Dassie!
That there is a Lazy Toed Arizona Varmint, ah tell you what. dem critters is good eatin!
It's not the right color for a whistle pig or a mountain beaver, although those are good guesses. Does anyone else think that it could be a Fluffyaplumpasaurus adoribilis? You can learn about them on comment 39. Granted, it's not quite as logical as my other suggestion (and that of several others) that it's a Richardson's ground squirrel, but possible nontheless. :-)
Those of us on the Richardson's ground squirrel bandwagon shoud really give great props to Rosel. She's the one who fist suggested it.
...is the person that she suggested it to alright? :-D
Indeed, Mega-Props to Rosel.
It would have taken me a while to Google-ImageSearch my way through the sciurids to narrow it down. Of course, if it isn' an RGS, then, well, we at least have someone to point at...
[lets see...about 14 more to go...]
er...OK, now its 14
OK, AnJaCo, can we now offically christen our little group the "Richardson's Ground Squirrel Bandwagon"? I think so. For short, it's the RGSB. We'll call Rosel the founder.
RGSB members so far:
Rosel (founder), Hai~ren, Mo Hassan, Boesse, Bret Schults, Mark Less, Corvid, Michael Erickson (me), and AnJaCo.
Anyone else who wants to join can. We don't descriminate.
Michael Erickson,
I'm on that bandwagon. And if it rains I'll try this one.
Which one should be the offical Richardson's Ground Squirrel Bandwagon's Bandwagon? The first one or the second one?
A rare short-legged chihuahua?
I kind of like the international flavor of the first one.
Maybe this qualifies as "something quite interesting about the animal, or about the group to which it belongs": Spermophilus is paraphyletic with respect to all of the other three other genera in Marmotini (sensu stricto, excluding chipmunks): Marmota, Cynomys, and Ammospermophilus are all derived Spermophilus.
Herron, Matthew D. et al. (2004): Sciurid phylogeny and the paraphyly of Holarctic ground
squirrels (Spermophilus)
AnJaCo, I think the first one is a good pick. I now cristen it:
the Offical Richardson's Ground Squirrel Bandwagon Bandwagon, or the ORGSBB for short.
Only five more comments after this one, and Darren will have his 100. Then maybe - just maybe - he'll give us the answer. So let's keep it moving! The end is in sight!
Domestic camelids have been eaten in emergencies, but they are not normally used as food animals because they breed too slowly.
Speaking og Gerbils, perhaps a Great Gerbil.
Rodent, Rats a luck or a FAT SAND RAT.
For those who haven't been Googleing RSG, the University of Lethbridge in Lethbridge, Alberta, Canada, has an active research program on these cute little nibblers and has a great deal of info on them at their web site. Life history, phylogeny, range map, pestiferousness, suitability as pets, PDFs, etc.
Of course it will all be just "interesting stuff" if the Rodent in Question is something other than RSG...
At this time of night, I suspect that Darren is in an altered state of consciousness, perhaps there will be 100 posts here by the time that he rises.
Here it is old chap, a Libyan Jind. Good night and lot`s of Rodent Dreams.
AnJaCo, what will become of the Richardson's Ground Squirrel Bandwagon once all this is over, and if the little guy turns out to not be a RGS after all?
That should be now that all this is over.
Michael Erickson, I'll call the tow truck, I have road coverage.
OK, that takes care of the Bandwagon itself. What do we do about the organization? What will happen to it?
Looking at the fur, for a moment I thought it might be a chinchilla, but the ears are wrong. The interesting fact about them is that the only way to make money is selling breeding stock to other people so they can get rich selling the fur. I wonder how many of those budding millionaires ever killed any.
Looking at the fur, for a moment I thought it might be a chinchilla, but the ears are wrong. The interesting fact about them is that the only way to make money is selling breeding stock to other people so they can get rich selling the fur. I wonder how many of those budding millionaires ever killed any.
Was googling around after finding out that Spermophilus was paraphyletic. There's now a new paper out that splits Spermophilus into 8 different genera. The Richardson's ground squirrel is now Urocitellus richardsonii.
Kristofer M. Helgen, F. Russell Cole, Lauren E. Helgen, and Don E. Wilson, 2009. Generic Revision in the Holarctic Ground Squirrel Genus Spermophilus. Journal of Mammalogy 90(2): 270-305.
I really cannot believe that a photo of a fat little rodent really brought in over 100 comments. Well done to you all, what fun. To those who said hyrax: shame shame shame on you, your skills at identifying mystery mammals need a lot of work :)
Thank you Johannes for Marmatogorgon: if only this were correct. Alas, those who suggested cane rat, pika, cavy, gerbil, hamster, dassie rat, gundi, Rabbit of Caerbannog, vole, lemming, whistle pig, mountain beaver, Lazy Toed Arizona Varmint, Fluffyaplumpasaurus adoribilis, short-legged Chihuahua, Awluk haucuteus, chinchilla, marmot or prairie dog were also, sadly, incorrect. As mooted by the members of the Offical Richardson's Ground Squirrel Bandwagon Bandwagon, or ORGSBB, it was indeed a terrestrial sciurid, and specificially a Richardsonâs ground squirrel Spermophilus richardsonii or Flickertail (there are other vernacular names too, as noted above). The huge genus Spermophilus has conventionally been grouped into eight subgenera, and Richardson's ground squirrel has usually been included in the nominate subgenus. However, recently phylogenetic work has scattered the different Spermophilus groups across the Marmotini, and has found that some of the conventional subgenera are polyphyletic. All of this means that Richardson's ground squirrel and its close relatives should now be referred to as Urocitellus (Spermophilus proper is restricted to Eurasia) (Helgen et al. 2009).
Random interesting facts: Richardson's ground squirrel (a denizen of central Canada, the Dakotas, Colorado, Nevada etc.) is colonial, constructing a complex tunnel system where there are usually eight entrances (the main entrance is marked by a mound). The burrows can be up to 15 m long. It can hibernate for 7 months (September-October to April-May) or more. Like other ground squirrels it utters a complex assortment of calls, some of which might be ultrasonic. It can hold over 1000 seeds in its cheek pouches at once. North Dakota is, apparently, sometimes called the Flickertail State after this species. The species sometimes occurs in huge numbers and is declared a pest, and Saskatchewan has been organising 'gopher derbys' as recently as 2004. And, yes, the captive one in my photo is atypically fat. More squirrelly stuff at some stage, for now... back to the dinosaurs.
Ref - -
Helgen, K. M., Cole, F. R., Helgen, L. E. & Wilson, D. E. 2009. Generic revision in the Holarctic ground genus Spermophilus. Journal of Mammalogy 90, 270-305.
Ha, I knew it! It really is ironic that the same day you posted this, I watched a rattlesnake eat one - which will appear in a long, morbid set of photos on my blog in a few days - stay posted y'all.
I guess I had about an hour to look at it slowly dissappear into the rattlesnake to remark upon its morphology, so I had an unfair advantage...
Bobby
P.S. some interesting facts:
-These guys burrow all over the MSU-Bozeman campus, and makes it look like MSU is infested by prairie dogs.
-In the off season hunters shoot these for sport, going out 'gopher hunting' - these are called gophers in MT.
-My girlfriend got in trouble because she had been asked to say something interesting about these critters when she was in 4th grade (kind of like on this thread, Darren...). She said 'they explode when you shoot them', and the teacher thought she was some kind of psycho. She had recently gone 'gopher hunting' with her dad...
That's hilarious :) Over the weekend I watched a stoat and some reed warblers, but I didn't see any exploding sciurids.
Addressing the Ceratosaurus/Majungasaurus semi-aquatic problem:
It's the fully marine reptiles that have somewhat backswept neural spines. Particularly mosasaurs--I suspect this helps keep the tail rigid. Of course, mosasaur tails also come in a wide range of shapes. Check out this image for some good examples.
Yeah, Ceratosaurus has pretty good-sized caudal neural spines, but that could just be a consequence of the dorsal neural spines ALSO being quite large. Remember that abelisaurs also have pretty tall neural spines, but their spineous processes are also quite tall, and abelisaurs had "flat backs."
And, in fact, Majungasaurus doesn't have particularily impressive caudal neural spines. Here's a skeletal from a recent paper about the critter's air-sac system for reference. It does have surprisingly short hind limbs, but I honestly don't see what that has to do with swimming. My corgi can swim if it really tries, but it doesn't like to, so the correlation between short legs and swimming isn't exactly concrete. What's more interesting to me about Majungasaurus is that the neck is quite long for an abelisaur.
I imagine that Majungasaurus hunted sauropods because, frankly, there were a lot of sauropods running around. I'm not saying that smaller vertebrates were off-limits, but sauropods would've been on the menu, too. They probably attacked sauropods much like allosaurs did, but might have been able to tear off bigger chunks of meat because of their (usually) bulldog neecks. Majungasaurus was doing something a little different, but the big teeth and robust skull point to a high-impact use of the chompers.
[from Darren: sorry, delayed by spam filter.]
Ha ha ha! I KNEW IT! IN YOUR FACE EVERYBODY WHO DIDN'T AGREE WITH ME! Ha ha ha! Losers! Just kidding :-)
Seriously, I know that those little things are supposed to be cute, but that pic is just crazy. That kind of cuteness outta be illegal...
Obviously a picture of the Hungarian Melon Eating Rat, Rous megalostoma, in a digestive rest. Oddly enough for rodents, several members of the Rous genus have no teeth at all, and must swallow their food whole. Some researchers suggest they should be placed in their own genus, Notarous, but there is still much debate and spilling of drinks going on in this regard.
Anyway, R. megs (as it is frequently referred to by lazy typists) has co-evolved to live exclusively in the melon, gourd and squash farms on the edge of the Hungarian pusta. Over time, the head/jaw skeleton of R. megs has become very loosely connected, even beyond that of the such famous jaw dislocators as Boa or T. rex. This adaptation extends to the clavicle and sternum, allowing R. megs to swallow objects substantially larger than their own bodies, common sense and good manners not withstanding. Even the plates of the skull disengage from each other and flatten out, which accounts for the stunned look of the specimen shown (who appears to have eaten a particularly large calabash).
The Hungarian farmers tolerate and even encourage R. megs, since once they have consumed a melon (or gourd or whatever), the rodent will retreat to the entrance of a burrow, where they will sit in a torpor for several days while digesting their meal and recovering from the associated concussion. This blocks the burrow from occupation by other, far more destructive, rodents such as rats, mice, and rabbits. If the burrow is already occupied, R. megs will usually usurp the burrow by simply lying down on the previous occupant and suffocating it.
During the melon (or squash, or whatever) season, R. megs may swallow as many as two melons (or whatevers) per week. The seeds are stored in a unique side pouch or diverticulum of the digestive system, and provide food during the animal's 9 month hibernation.
In the mating season, which coincides with late melon season, male R. megs will engage in dominance combat rituals. This usually starts out with eructation, fur erection, and gaping displays, but rapidly escalates into an all out struggle in which one male attempts to dominate the other by lying down on top of him. This is like trying to stack two furry, wiggly, slow moving soccer balls, and is about as successful. Individual combats can last for many hours, at the end of which the winner usually collapses from exhaustion while the loser (who generally has conserved his energy by simply lying on the ground) waddles off and mates with the other male's harem.
Zach Miller: That Majungasaurus skeletal is VERY inaccurate. I've heard several people more knowlegdeable than myself say so. Check out Scott Hartman's skeletal over at DeviantArt. That's the correct one. To me, it looks aquatic. It's tail agrees pretty well with that of a crocodilian or, better yet, a phytosaur. The legs are VERY short.
"I honestly don't see what that has to do with swimming."
Huh? Terrestrial crocs (like Priostichamsus) had long hind limbs. Modern amphibious crocs have very short (by comparison) hind limbs. A corgi, a breed of dog, a tiny mammal selectively bred by humans, does not make a good comparison for a giant archosaurian reptile.
After you look at the skeletal, please tell me what you make of it. It just looks like an aquatic animal to me. Now, let's just assume for one momment that I'm correct (and I have no problem with the possibility that I'm not). Maybe the aquatic adaptaions I think I see in the reptile were part of its sauropod-attack stradegy. What if Majungasaurus floated in the watering hole like a croc, waiting for some unlucky sauropod to come for a drink. Then - Surprise! *theropod explodes out of the water, rips a huge, bloody, crippling chuck out of the sauropod, kills the animal, eats it, the end.*
Not that this affects the sauropod-killing idea in any way, but the teeth of Majungasaurus are small in comparison to the rest of the skull, not big.
Holy crap, Michael--that thing is WIERD! And I do trust Scott's skeletals. Things I find impressive:
1) Look at the size of those cervical ribs!
2) How does the darn thing balance on those short little hindlimbs?
3) My, what tiny teeth it has!
4) The thing only stands less than two meters off the ground: that's shorter than you or me. I sense we could kick Majungasaurus in the face if need be.
5) The caudal neural spines are quite tall, but about as tall as those of Ceratosaurus, and they're not backswept. I'm betting the tail is tall and heavy to counterbalance the front of the animal.
6) Again: Look at those short little legs!!!
NO idea what Majungasaurus was doing. It almost seems like the legs don't go with the rest of the skeleton! I don't think it was going after sauropods--sauropods would just STEP ON IT!
Zach,
Rapetosaurus wasn't a particularly large sauropod...
clheiny: I'll be watching for you from now on.
Let this be a lesson: never eat anything bigger than your whole body.
I know it, Zach, buddy! It very well may be that the tail is huge and heavy to couterbalance the rest of the freakish critter. But..
Reasons I think that maybe it's semi-aquatic:
1) Good tail-propelled swimmers often (but not always) have vertical caudal nueral spines. Although there are some tail-scullers (like mosasaurs) with backswept caudal neural spines, I know of no fully terrestrial reptile with vertical caudal neural spines; all reptiles I can think of with this feature are semi-aquatic.
2) How DOES that freakish thing balance on those puny hind legs? That's what made me think that it didn't even try too often, because it wasn't a full-time land-dweller.
3) WHY are those dang legs so short? The terrestrial ancestors of crocodilians had very long legs, and modern amphibious crocs have very short legs. Maybe the same sort of aquatic-lifestyle-shortend-limbs thing was going on with Majungasaurus?
4) This one is very speculative - But maybe those teeth were small 'cause they were for ripping up fish, not land animals????
5) Another tentative one - Was the head heavy, powerful, and stress-resistant for attacking big turtles?????? (Just crazy speculation.)
Let me know what you think, Zach. (P.S. I love When Pigs Fly Returns!)
Glad you like the blog, brother. Expect part 3 of the "Horns & Spikes" series soon. I'm warry of the semi-aquatic hypothesis mainly because all semi-aquatic or fully aquatic vertebrates I can think of lose their hind limbs, not their forelimbs, or retain good-sized hind AND forelimbs. I suppose it's something I'd have to see (I'll have to draw it to really understand it--I know, it's wierd).
Ichthyosaurs are tail-driven, but they have pretty weaksauce caudal neural spines. Of course, they also developed a tail fluke, soooo yeah. I can certainly see Majungasaurus as a perfectly capable swimmer, but aside from its "tall" tail, it doesn't have a whole lot of aquatic adaptations, especially toward the front end. If it were eating fish, you'd expect the teeth to be bigger, thinner, maybe interlocking.
I'd be tempted to suggest that it's a bottom-walker, but it lacks pachyosteosis bones and, in fact, shows lots of pneumatic bones instead. If anything, Majungasaurus was an excellent floater! Great discussion, though. Scott's drawing really has my mind reeling.
Yeah, Zach! That's what i've been thinking the whole time, Majungasaurus floating around at the surface of the water, stupidly long (for an abelisaur) neck and head held clear of the water, and tail sweeping slowly side-to-side, with shorty-short-short hind legs kicking. If it was a fish-eater, I would indeed expect more spinosaur-like dentition. But then again, sharks? Anyway, I totally get what it is to not understand something 'tll I draw it. You draw prtetty good dinosaurs, and I think that I do, too. Want me to draw a water-loving Majungee and send it to you?
It would be based on Scott's skeletal, of course. That freakish thing is just.. Freakish!
Let us not forget that Majungasaurus is known to have eaten Majungasaurus (based on the tooth marked longbones).
Also, it's hindlimbs are short BY THEROPOD STANDARDS. But compare these to bipedal crurotarsans or even big ornithopods: they aren't stupidly short in that context.
Err.... squirrels? :)
Oh screw squirrels! Stinkin' mammals... ;-)
But Tom, Majungasaurus is considerably larger (and heavier) than Effigia or Shuvosaurus. I'm just wondering how it managed to keep from looking like a drinking bird while walking around. (LOL)
I forget that they ate each other. Maybe they swarmed carcasses like Komodo dragons do, and Deinonychus might've, and a few conspecifics were torn apart in the process? There were big carcharodontosaurs around at the time too, right? Maybe Majungasaurus was the resident small-vertebrate-eater-and-scavenger?
Michael: thanks for the compliment. Yeah, shoot me a picture at my sillysaur email address. I'll draw up a picture myself and put it on my blorgh.
Guys - stop posting comments now, a dedicated article on the subject is coming within the next few minutes...
Ouch.
However, I'm still laughing at all the rest :-D
If both of you are in the NBA!!! Ordinary people are not 2 m tall, except in, like, southern Sudan.
Nope. Maastrichtian.
:-D :-D :-D
*looks behind* Gosh, a whole bandwagon.
There was a post on these critters a couple of days before this post at Urban nature so the picture just clicked.
http://community.livejournal.com/urban_nature/238136.html#cutid1
a vote for Hyrax
Dude, this guessing game is over with. The thing ended days ago! Besides, it looks absolutley nothing like a hyrax, and Darren's already told us what is (comment 108).
ive got it! its a irratiated fig nuton. other wise known as a figeranus nutagonapus