First, remember our friend Spinosaurus from Jurassic Park 3? Easily the coolest creature in a very uneven creature feature, the onscreen predator was just as much at home swinning up on people submerged as it was fighting T. rex. Scientists have debated for a long time how aquatic Spinosaurus was. Did it swim, or was it just an occasional wader? The fragmentary nature of available skeletal material didn't answer that. Now we know: Spinosaurus apparently was equipped for a crocodile-like lifestyle, tethered to the land but hunting fish, reptiles, and other dinosaurs in the rivers and shallows, snatching animals in the water or perhaps ambushing them as they came down to drink (which must have been hard with that sail). We know this because we have good fossils of the tail now, and it's a crocodile-like tail, flattened side-to-side, suited for propulsion for an animal that also shared the crocodilian tendency toward short legs and (we think) webbed feet. It was the first true swimmer we know of among the dinosaurs. The key fossils came from Morocco and were unearthed in 2017-18.
Coverage here from Nat Geo
Spinosaurus at the George S. Eccles Dinosaur Park-Museum, Odgden, Utah Rea;;y cool, but we didn't know about the tail. Photo by Matt Bille, 2018.
About unearthing dinosaurs. I've always wondered if some ancient traveler saw a Spinosaurus eroding out of a cliff and saw the sail as a pair of wings folded up. "So that's what a dragon looks like!"
The biggest dinosaur search of all time, called Mission: Jurassic, is on in Northern Wyoming, near the famed Morrision Formation. Here's a fascinating story about the riches being uncovered and how one scientist has committed the next 20 years of his life to excavating the site.
Allosaurus, a common denizen of the Mission: Jurassic site and the Morrison Formation (photo origin unknown)
I am an amateur scientist and historian developing a multidisciplinary conjecture. I know that the Earth is at least 4.5 billion years old. However, my conjecture indicates that the megafauna lived during a climate much warmer than our present climate that occurs every 26,000 years. The problem is that this would indicate that giant reptiles would exist at the same time as the megafauna. Not that they would be dinosaurs. They would be reptiles like today, but giant, just as the giant cheetah is recognized by consensus science as the same species as the present cheetah and the Dire wolf is (in my conjecture) a giant grey wolf, and as Megaloceros is a giant deer. Yet there have been very few giant Quaternary reptiles recognized by accepted professional science. So this path leads me to listening to creationists (credentialed scientists) of the old Earth and young Earth varieties as they argue over soft tissues in dinos. Having read some articles by professionals (not creationist) as well, it seems to me that, if the tissues are endogenous, then they are probably not older than 2.7 million years. There has been a strong trend among reputable professional specialists (even publishing in 2020) to accept these tissues as endogenous on one hand. On the other hand some maintain on good ground that they are not endogenous on the grounds that they could not have survived that long (e.g. a Mr. Buckley). I wonder what thoughts you might have on this?
ReplyDelete*Dinosaur Blood and the Age of the Earth by Rana
*Echoes of the Jurassic Discoveries of Dinosaur Soft-Tissue (the book) by Anderson
* 2011, Buckley, "Collagen survival and its use for species identification in Holocene-lower Pleistocene bone fragments from British archaeological and paleontological sites"
*2017, Buckley, "A fossil protein chimera; difficulties in discriminating dinosaur peptide sequences from modern cross-contamination"
*2020, "Evidence of proteins, chromosomes and chemical markers of DNA in exceptionally preserved dinosaur cartilage"
Alida M. Bailleul 1,2,∗, Wenxia Zheng3, John R. Horner4, Brian K. Hall5,
Casey M. Holliday6 and Mary H. Schweitzer
*2019, "Cretaceous dinosaur bone contains recent organic material and provides an environment conducive to microbial communities"
BRITANNICA WIRE: Fossilized dinosaur tissue discovered | Encyclopaedia Britannica
ReplyDeletehttps://www.youtube.com/watch?v=B_9Y9sdJbF4