Desert’s quicksand by ~T-PEKC
“This is my second entry for “All Your Yesterdays” paleoart contest. While the concept may not be pretty original, some of the details and interpretations of the fossil material actually are. Below is description of the artwork. If you’re interested to know which parts of this artwork are speculative, please take time and read it.
Unusual interpretation of one of the typical paleoart memes – big herbivore stuck in specific substance, surrounded by bunch of predators waiting for easy meal. The scene takes place in what’s now Zimbabwe (Africa) some 190 million years ago, near a desert oasis where an adult individual of Massospondylus carinatus is stuck in a dry quicksand. Hours later, when the dark fell, the sounds of the trapped animal attracted some small theropods – Megapnosaurus rhodesiensis. Because of the much greater size of the prosauropod they just waiting for time to do its job and weaken the stuck dinosaur. All that Massospondylus got left is to use its inflatable dewlap in attempt to scare off the little carnivores.
Environment – both of the depicted species of dinosaurs are known to have (at least partially) inhabited desert regions with sand dunes and oasisaes.
Dry quicksand – unlike normal quicksand, the dry quicksand doesn’t contain water. It forms when fine sands reduce their density by blowing air trough it. For more information on the dry quicksand, take a look here - [link]. Given the mechanism of forming dry quicksand what’s better place to get stuck in it than a sand desert, where constant winds change the landscape by moving sand particles.
Why during the night? – While during the day the temperatures in deserts are usually too high for (big) animals to wander through the sandy landscape, during the night the weather is colder, sometimes even cold. This change in the temperatures probably forced dinosaurs living in such region to be more active at sunset or during the night. A study of the skleral ring and orbit morphology of various dinosaurs indicated that some prosauropods and a species of Megapnosaurus were probably nocturnal animals, and this was used to back up their depictions here.
Massospondylus – although this ‘prosauropod’ is known from complete remains, its appearance here is quite speculative. I restored it with very big inflatable dewlap used for intraspecific and interspecific visual display functions. Many modern birds pose such structure, and maybe the same applied to variety of non-avian dinosaurs. The keratinous spikes along the dorsal part of the body are based on fossil evidence from Diplodocus, and the scaly integument is reconstructed after what’s known for Sauropodomorpha’s integumentary structures. Recently published paper describing tail amputation in possibly specimen of Massospondylus directly inspired this reconstruction. Here, the animal lost the distal part of its tail probably after attack of the theropod Dracovenator, which lived in the same time and place. The “coloration” pattern of the animal is similar to sand’s ripple-marks, and it is supposed to help the ‘prosauropod’ to blend better with the environment (sand dunes).
Megapnosaurus – reconstructed with pair of hypothetical low keratinous crests. Protofeathers are also speculative at the moment, only because there is no direct evidence for their presence in so basal theropods. As one of those people who support the idea of some kind of dorsally located keratinous integumentary structures being basal trait of Dinosauria, I think the presence of protofeathers (to some degree) in primitive theropods is not that far-fetched. Also, dino-fuzz could have been of benefit for the animal, increasing its termoregulatory efficiency during the cold desert nights. Of course, the visual display functions of protofeathers, especially in intraspecific interactions such as mating rituals, is beyond a doubt here. Megapnosaurus’ “color” pattern is based on the bird Oenanthe deserti.
Butler, R. J., A. M. Yates, O. W. M. Rauhut, C. Foth. 2013. A pathological tail in basal sauropodomorh dinosaur from South Africa: evidence for traumatic amputation?- Journal of Vertebrate Paleontology, 33, 224-228.
Chiappe, L. M., R. A. Coria, L. Dingus, F. Jackson, A. Chinsamy, M. Fox. 1998. Sauropod dinosaur embryos from the Late Cretaceous of Patagonia.- Nature, 396, 258-261.
Czerkas, S. A. 1992. Discovery of dermal spines reveal a new look for sauropod dinosaurs.- Geology, 20, 1068-1070.
Paul, G. S. 2010. The Princeton field guide to dinosaurs.- Princeton University Press. (referenced for skeletal drawing of Megapnosaurus)
Schmitz, L., R. Motani. 2011. Nocturnality in dinosaurs inferred from scleral ring and orbit morphology.- Science, 332, 705-708.
Skeletal drawing of Massospondylus by Scott Hartman - [link]
Unfortunately the lowermost part of the artwork was cut off by the scanned, and this is the reason why part of the foot of the right Megapnosaurus is not visible, which greatly affects composition. Tried to scan the image again but got the same result, dunno why.
Medium: Pencil (2B and 5B) on yellow paper (+ digital editing with Photoshop CS3).
Time spend on this artwork - 20+ hours.”