Shop Mobile More Submit  Join Login
Sonorasaurus thompsoni by Paleo-King Sonorasaurus thompsoni by Paleo-King
Etymology: "Thompson's Sonoran Desert lizard" (after the Sonoran Desert in Arizona and for then-student of geology Richard Thompson)

Time horizon: Mid-Cretaceous, Albian-Cenomanian stages (~112-93 mya)

Length: ~17m (~55.7 ft.)

Probable mass: 20 tons, perhaps more based on maturity

Sonorasaurus was a late-stage brachiosaur (in fact probably as late-stage as you can get in this family's evolutionary history, without bringing up that quasi-crypto report of brachiosaur tail material in Mexico from supposedly Maastrichtian-age rock layers). As a result this is a very important animal for understanding the changes undergone by the group during the Cretaceous, a time when they gradually went from being incredibly successful survivors of the LJ-EK mass extinction, to being increasingly rare and out of their element. This is clear at least in North America, where the inland sea and increasingly swampy climate during the mid-Cretaceous gradually pushed all surviving sauropods (brachiosaurs, chubutisaurs and other basal titanosauriforms) towards extinction. Due to the lack of extensive research on cretaceous brachiosaurs elsewhere, it is hard to tell exactly what caused them to die out or how long they actually survived into the Cretaceous before being fully supplanted by titanosaurs (they seem to have dominated England for a long time, and tantalizing clues about their Cretaceous presence in Argentina, Lebanon, and even China have turned up).

Sonorasaurus was described by Ron Ratkevich in 1998, an quickly brought attention to Arizona as a dinosaur state. Yet it failed to become Arizona's state dinosaur. One thing notable about this species is that its basic design, specifically the arms, seems little changed from far older Jurassic brachiosaurs, indicating either that it's from a particularly old bloodline within the group (perhaps akin to B. altithorax) or that brachiosaurs in general changed little over their history. It does, however, appear to be different and more basal in morphology than the Cedarosaurus-Abydosaurus lineage, though there are still a lot of unanswered questions about this animal and any full-body reconstruction so far still requires a lot of speculation. A cast of the arm as well as the the original dig site is on outdoor display near the Sonoran Desert museum where its bones are housed (next to a rather ugly mid-90s style water fountain :P).

Like Cedarosaurus, there were stomach clasts found with this animal, which further indicates that even brachiosaurs were not chewers, though they were better adapted to hacking through tough branches than diplodocoids. The remains indicate very long and gracile hands, but much more compact hindfeet, even by brachiosaur standards. Ratkevich intially mentioned a crushed skull being found with the skeleton, though on closer analysis by Curtice (2000) the object turned out to be a vertebra. Interestingly enough, a music app for iPhone has been named after Sonorasaurus: www.sonorasaurus.com/

REFERENCES:

Curtice, B., 2000, The axial skeleton of Sonorasaurus thompsoni (Ratkevich, 1998): Southwest Paleontological Symposium, Mesa Southwest Museum Bulletin, v. 7, p. 83-87.

Ratkevich, R (1998). "New Cretaceous brachiosaurid dinosaur, Sonorasaurus thompsoni gen et sp. nov, from Arizona." Arizona-Nevada Academy of Science 31; 71-82.
Add a Comment:
 
:iconbricksmashtv:
bricksmashtv Featured By Owner Jun 19, 2016  Hobbyist Traditional Artist
Nima, there's a new paper on Sonorasaurus! file:///home/chronos/u-89f2a75e875d8dc15b31eb18610ecada3244df0c/Downloads/Sonorasaurus%20Reassessment%20(1).pdf
Reply
:iconpaleojoe:
PaleoJoe Featured By Owner Mar 24, 2016  Student Traditional Artist
It's neat that this Brachiosaurid is from my home state, Arizona. Great job as always.
Reply
:iconpeteridish:
PeteriDish Featured By Owner Mar 24, 2016  Hobbyist Photographer
that's one overgrown turkey... :D
Reply
:iconteddyblackbear2040:
TeddyBlackBear2040 Featured By Owner Mar 24, 2016  Student Digital Artist
Nice detail and information.
Reply
:iconthedinorocker:
thedinorocker Featured By Owner Mar 21, 2016
Nothing against Sonorasauris, but I am waiting only for yours updated Giraffatitan skeletal! :)
Reply
:iconpaleo-king:
Paleo-King Featured By Owner Mar 22, 2016  Professional Traditional Artist
Lol I know. I am working on that, despite all indications :D The top view is just a pain, I'm done with all the other views.
Reply
:iconthedinorocker:
thedinorocker Featured By Owner Mar 22, 2016
I hope to see your work soon;)
good work!
Reply
:icondontknowwhattodraw94:
Dontknowwhattodraw94 Featured By Owner Mar 21, 2016  Hobbyist Traditional Artist
Nice skeletal, didn't know about this one :)

I find it surprising how brachiosaurids are quite famous if they're from the Jurassic, but Cretaceous ones seem to get ignored.
Reply
:iconpaleo-king:
Paleo-King Featured By Owner Edited Mar 21, 2016  Professional Traditional Artist
You make a good point. Now the real kicker is, in terms of numbers of papers published, ALL brachiosaurs tend to be relatively ignored. There's fossil material in museums across the Rockies states that could represent up to seven different brachiosaur genera, yet none of it has been described and it's just sitting there. Meanwhile every little fragment of raptor feather is having ten papers written about its chemical composition, and even diplodocids get a whole lot more descriptions (Kaatedocus, Galeamopus, Leikupal, etc...). Yet we don't have a valid description of any Morrison Formation brachiosaur since B. altithorax (1903!) despite there being several different species in the fossil material. And that doesn't even start to get into all the undescribed Cretaceous material from the Cloverly and Cedar Mountain formations. I mean I don't have actual proof of any conspiracy, but WOW.....
Reply
:icondontknowwhattodraw94:
Dontknowwhattodraw94 Featured By Owner Mar 22, 2016  Hobbyist Traditional Artist
That's indeed weird. You're right about raptors or theropods in general getting most of the attention if you just look at what gets featured in the media and such. 
It surprises me though that the tallest land creatures are so ignored, you'd expect a bunch of scientists at least spending a part of their carreer studying them.
Reply
:iconpaleo-king:
Paleo-King Featured By Owner Edited Mar 22, 2016  Professional Traditional Artist
Indeed. But you see very few big names in paleontology giving them much notice. I've heard at an SV-POW conference that there are over 30 specimens of Bracihosaurus itself, but good luck finding any photos or catalog numbers for over half of them.

This is the other big problem with a lot of the pointless curmudgeon controversies out there in JVP-land (sluggish scavenging T. rexes, "Toroceratops", PachyDracoStygiRex, and so forth...) - they TAKE TIME AND TALENT AWAY from far bigger areas of dinosaur research that sorely need a LOT more attention from PhD-level professionals. I don't even know WHY entire teams of doctorate holders are spending so much time "burning down Rome" over a couple ceratopsian taxa that have been well-known for over a century and in any case are already very closely related even when you don't resort to outright denial of their multiple differences :X, when there are SEVEN undescribed colossal brachiosaur genera, all unique, some very recently excavated, that aren't even being touched. Honestly it seems the only people who know anything detailed about most of the unpublished American brachiosaur material are part-time museum volunteers at BYU and other, much smaller and poorer museums. :X :X :X
Reply
:iconthedinorocker:
thedinorocker Featured By Owner Mar 22, 2016
So this is pretty sad... 30 specimens of Brachiosaurus and I have memory of less than 10, and can t remember more than a few photos (the holotype homerus a  couple of vertebrae and the skull of the cf.Brachiosaurus quarry).
And I don t even spend a word for the seven undescribed genera...
Reply
:icondontknowwhattodraw94:
Dontknowwhattodraw94 Featured By Owner Mar 22, 2016  Hobbyist Traditional Artist
I sense some frustration there xD

But no, you're right. I'd love to get to know some new giant sauropods that aren't titanosaurid. Hope those fossils are going to get described at some point.
Reply
Add a Comment:
 
×
  • Art Print
  • Canvas
  • Photo




Details

Submitted on
March 21, 2016
Image Size
1.2 MB
Resolution
2984×3336
Link
Thumb
Embed

Stats

Views
1,041 (4 today)
Favourites
36 (who?)
Comments
13
×