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TSoSC#4 = Lariosaurus goes for a stroll

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Triassic Seas of South China #4 = Lariosaurus goes for a stroll

Acrylics, digital and photography, 2014

created for = Qiyue Zhang, Wen Wen, Shixue Hu, Michael J. Benton, Changyong Zhou, Tao Xie, Tao Lü, Jinyuan Huang, Brian Choo, Zhong-Qiang Chen, Jun Liu & Qican Zhang (2014) Nothosaur foraging tracks from the Middle Triassic of southwestern China, Nature Communications 5, Article number: 3973 doi:10.1038/ncomms4973  

ca. 245,000,000 bp, Middle Triassic (Anisian), Luoping County, Yunnan, China (Member II of the Guanling Formation)

A small nothosaur (Lariosaurus cf.hongguoenis) forages on a shallow seabed in search of lobsters and small fishes. It propels itself along with rowing motions of it's paddle-like forelimbs, leaving behind distinctive prints on the sediment (ichnotaxon Dikoposichnus luopingensis).

The Luoping Biota of Yunnan (gogosardina.deviantart.com/art…) is already well known for its outstanding body fossils of a Triassic marine community. However, when Qi-yue Zhang, of the Chengdu Center of the China Geological Survey, was mapping geological features near the village of Daaozi, he noticed several track marks on a ledge. The team dug up the area on the ledge and exposed 350 exquisitely preserved prints that formed about 15 different trackways. Each print is a narrow V-shaped slot-like depression with a mound of sediment behind it.

The spacing and contours of these tracks perfectly match the fore-paddles of nothosaurs. They're too big to be made by pachypleurosaurs, lack the distinct clawed-digits of placodonts, saurosphargids and thalattosaurs, while are outside the range of motion possible for ichthyosaurs.

The trackways fall into small (35-42cm outer width) and large (50-67cm) size classes. Complete body fossils of two species of nothosaurs, the small 80cm Lariosaurus hongguoensis and the much bigger (2-4m) Nothosaurus yangjuanensis, are known from the slightly younger Panxian locality, both of which are likely creators of these prints.

The trackways provide the first direct evidence of sauropterygian swimming behaviour. The nothosaurs moved along the seafloor by punting their forelimbs in unison rather than with an alternate back-and-forth motion. This may have implications with reconstructing how other sauropterygians (ie. plesiosaurs) swam.
Image details
Image size
3760x1848px 3.34 MB
Make
Canon
Model
Canon PowerShot S50
Shutter Speed
1/807 second
Aperture
F/2.8
Focal Length
7 mm
Date Taken
Jan 3, 2008, 12:34:43 PM
Sensor Size
10mm
Published:
© 2014 - 2021 Gogosardina
Comments40
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DemandHandimation's avatar
I cannot even believe this is a painting! I love in particular the way you portray the murkiness and lighting in these underwater scenes. The detail is just absolutely incredible!
Gogosardina's avatar
Many thanks, glad you like it.
DemandHandimation's avatar
NP! Top notch Paleoart my friend!
vasix's avatar
I still have so many questions concerning these faunas, they're so fascinating ugh...anyway I looked up the Nothosaurus zhangi paper just now, and the paper anyway states that Panxian is equivalent in time to the fauna with N.zhangi...would that also be younger than the first TSoSC animals? The paper mentions Phalarodon atavus as a contemporary...Dinocephalosaurus and Atopodentatus too, as well as a mixosaur like Mixosaurus panxianenensis. Just wanted a little bit of clarification on the dates and...whatnot. :) 
Gogosardina's avatar
Both the Panxian biota in Guizhou and the Luoping biota in Yunnan are in the Guanling Formation in sediments that are dated to the Anisian (Pelsonian) on the basis of conodonts and radiometric dating. Of the two, the Luoping is slightly older than the Panxian. There is comparatively little overlap between the 2 faunas so they probably represent a quite different suite of habitats. 

The Guanling Fm is divided into 2 members = The lower one is 333 m thick, and consists of calcareous silty mudstone and mudstone intercalated with muddy dolomite (= transition from restricted-evaporitic tidal flat to shallow marine facies.)  The second member, which is the one with all the cool articulated fossils, is a 580 m thick succession of limestone, in some places with bands of dolomite. 

Luoping occurs in the middle part of Member 2. Panxian occurs in the top section of Member 2, just below the border with the overlying Yangliujing Formation.
vasix's avatar
Thanks for the information...also, I saw here: www.bioone.org/doi/abs/10.1080… that S.sikanniensis might be a Shonisaurus species rather than a Shastasaurus...might it really be possible? 
aetArtakTorosyan's avatar
MooMinded's avatar
When I first saw this, I honestly thought this was a photograph... the level of detail here is just superb. Amazing work! 
Manuelsaurus's avatar
Fantastic work , so look very realistic
koganeii's avatar
You sure this is not a photo? WOW
Justisaurus's avatar
Holy crap! omfg That looks so incredibly realistic it looks like you actually went back in time to the Triassic period's ocean and took a photograph of a strolling underwater Lariosaurus! Excellent job, this is easily one of the most lifelike pieces of paleoart I've ever seen :D
Gogosardina's avatar
Thanks, illustrations for scientific papers like this one come under extra scrutiny so I made an extra effort.
Justisaurus's avatar
Well it certainly paid off! Great job! :)
dinodanthetrainman's avatar
It looks like a photo! :)
Gogosardina's avatar
Yeah, its composed like a dive photo (illuminated by a flashbulb from the viewer's camera)
shellz-art's avatar
Unbelievably amazing.
MoonyMina's avatar
aspidel's avatar
Quite an unusual behaviour to say the least. And perfectly rendered. It almost looks like a photo! +fav
Orionide5's avatar
It's like a reptile penguin!
Gogosardina's avatar
Or a penguin is like an avian nothosaur!
pilsator's avatar
Congrats on the paper, and Lariosaurus has always been awesome.
Dontknowwhattodraw94's avatar
Never heard of this seareptile before, but nice work: it looks very realistic :)
Also, that's an amazing discovery those swimming prints. It's weird how such tracks can fossilize. 
AlexSone's avatar
Great work! Looks like alive!
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