Monday, March 15, 2010

Reconstructing Ichthyosaurs

Welcome to Grade 1:
"Alright students, what does an ichthyosaur look like?" 
"They look like dolphins!"  "Whales, like whales!"  "Yeah FISH!!!"  "SHAAARKS!"  "Ooo ooo, Mr. Bond, oooo???!"
"Yes, Billy?"
"Miga!  They look like Miga!"  "YEAH!!! MIGA!!!"  "MIGAMIGAMIGAAAAA!!!!"
"Settle down CHILDREN! CHILDREN! Ugh..."

Miga, for the uninitiated, was an Olympic mascot here in Vancouver - part bear and part orca.  I assume it is the orca that Billy, the made-up child in this real-life situation, is relating ichthyosaurs to.  Dolphins, whales, fish, orca - ARE ichthyosaurs so similar?  Or, like Miga, more of a mix of creatures?

Or are we just imposing our understanding of extant animals upon extinct ones?  What did ichthyosaurs look like?

With these beautiful aquatic reptiles being the focus of ART Evolved's next Gallery, I thought we should begin discussing how exactly they should be reconstructed.  What are the current controversies palaeo-artists are dealing with when restoring ichthyosaurs from fossil to flesh?

Darren Naish (at Tetrapod Zoology) recently (Sept. 2008) discussed a few of the assumptions we make when we think of what ichthyosaurs look like and how they behave.  Did they really have dorsal fins?  How much of our knowledge of ichthyosaur body shape was faked by unscrupulous preparators?  Most aquatic swimmers (fish, dolphins) have a dorsal fin, two pectoral fins and a powerful tail.  Why did ichthyosaurs retain their two hind-fins?  In an older article, Naish ponders the question: Did they use their pectoral fins and "fly" underwater? 

There are also a few questions I'd like to ask here, confronting the traditional view about ichthyosaurs:
1) Was their skin slick and smooth like a dolphin, or bumpy and scaly like a monitor lizard?
2)  Did they eat only squid and ammonites?
3)  Did all genus of ichthyosaur reproduce through live birth?
4)  Did they partake in cannibalistic behavior?
5)  What did the huge Shonisaurs eat?
6)  Could I have ridden one?
7)  Isn't there an easier way to spell "ichthyosaur?"  Maybe with less h's?

I am hoping that some of our readers might have some insight into the World of Ichthyosaurs!  Help us reconstruct more accurate creatures!  Speak up!  We won't bite! ...much!

And to get our collective ichthyosaur brains working, watch this They Might Be Giants "Nine Bowls of Soup," staring Mr. Ichthyosaur...


Neil said...

1) No reason to think that they had lepidosaur-like integument 2) Definitely no 3) That seems to be what the phylogenetic optimization studies are saying these days 4) Probably, most animals do, at least occasionally 5) Shunosaurus is a sauropod -- Shonisaurs? Cephalopods seems like a pretty good bet 6) I'm gonna say no 7) it's not so hard really.

Alright folks, let's see some kick-ass Xinminosaurus reconstructions!

Neil said...

I'll throw out Himalayasaurus and Guanlingsaurus as other fun, if challenging, projects.

Peter Bond said...

Yikes! Thanks Neil for catching that spelling error - the post has been tweaked...

Challenging reconstruction wish list!

Brian Blacknick said...

I'd think they had some sort of dorsal fin to prevent rolling and to add stability while swimming.

Probably a good bet they would dine on smaller members of their clan when the opportunity presented itself.

Rachael said...

9 Bowls of Soup! the creator of which was most likely on illegal substances.

Tail constructions are always rendered as fish tails. Is there evidence that there was an upper part to the tail equal to that of the lower part?

Bristol museum in England has some amazing fossils of these creatures. I'll post some info. Unfortunately they do not have much info online. Need to get down there again this week and do some sketching and note taking so I'll share what I have with you all.

davidmaas said...

Good idea Racheal. I'll try to get some photos from the Stutgart museum as well.

Albertonykus said...

Miga? Ha ha ha... XD

Bruce Earl said...

Did i ever tellyou about that time.. me and jessica wet to the beach to look at som corals when a Othelmosaur came and almost bit me in the leg...Fun times :)

John said...

In regards to the Shonisaur question-- I've been pondering that myself while I try to reconstruct one for the upcoming Time Capsule. They're big like whales, so it's tempting to imagine them filter-feeding like the mysticeti. However, while that would be a pretty cool-looking ichthyosaur, the snout seems a little too narrow for this mode to be effective. I'd imagine they most likely ate fish and belemnites.
The more interesting question for me is HOW they fed. Since the teeth are either reduced or absent, I'd imagine they wouldn't have been able to get a very good grip on prey. I think they could have fed by suction-feeding as modern-day beaked whales do, by rapidly depressing the hyomandibular bone (or perhaps expanding throat muscles in the ichthyosaur's case). Interestingly enough, the skulls of some beaked whales (especially Gray's Beaked Whale) have an unusually long, narrow snout like shonisaurs-- though in the whales it's padded out by fat and muscles.

Dinorider d'Andoandor said...

kids can be really cute and funny!