Palaeontology Round-Up 16-11-2009
Long Neck Ancestor Found
A new species of dinosaur called Aardonyx celestae from the early Jurassic period in South Africa reveals that the giant sauropod (long necked) dinosaurs started reaching their massive sizes at an earlier stage than expected. The specimen was about 7 metres long and died when it was 10 years old, so would have had a decent amount of rowing left to do before reaching it’s full size.
| Yates elaborates on the anatomy of Aardonyx celestae: “The dinosaur had a wide-gaping mouth, bracing joints in the back vertebrae that made the backbone rigid enough to support great weight and a forearm and hand capable of grasping and supporting weight. Growth rings in the rib and shoulder blade sections show that Aardonyx was not full grown — it was probably less than 10 years old when it died near a river or stream.”
He adds: “Aardonyx probably walked on its hind legs but could drop onto all fours as well. It had flattened feet with large claws that supported body weight on the inside of the foot and a robust thigh bone (femur) for supporting weight.” |
Full article here.
The right premaxilla, a bone from the tip of the snout. The two prongs partly enclose the giant nostril characteristic of this species. The tips of two teeth can be seen protruding from the bottom edge. (Credit: Image courtesy of University of the Witwatersrand)
Video about the discovery here.
And pics:
Top illustration by Matthew Bonnan, middle and bottom illustrations by Adame Yates
| According to paleobiologist Martin Brasier of Oxford University, the gooey droplets suggest that spiders were starting to spin webs that were better adapted for catching flying insects. “Interestingly, a huge radiation took place in flying insects and bark beetles about 140-130 million years ago,” Brasier wrote in an email to Wired.com. “So we may be seeing a co-evolution of spiders and insects here.” |
Full article here.
Now, to mount it on my wooden cane…
| the Falklands wolf’s closest living relative is actually the maned wolf — an unusually long-legged, fox-like South American canid. The researchers also found that the four Falklands wolf samples that they examined shared a common ancestor at least 70,000 years ago, which suggests that they arrived on the islands before the end of the last ice age and before humans ever made it into the New World. That rules out the prevailing theory that Native Americans had anything to do with their presence on the islands.
“The biggest surprise was that the divergence of the Falklands wolf from its closest living relative, the maned wolf, occurred over 6 million years ago,” Slater said. “Canids don’t show up in the South American fossil record until 2.5 million years ago, which means these lineages must have evolved in North America. The problem is that there are no good fossils that can be assigned to the Falklands wolf lineage in North America.” |
Full article here.
While the animal was first discovered in 1910, it’s place in theropod (the family of dinosaurs containing the two legged meat eaters) evolution has been something of a mystery. It was fist identified as being a species of Megalosaurus, as many were back in the day (the name Megalosaurus is often referred to as a ‘waste basket’ name because of this).
In 1926 it’s name was officially recognised as being different to Megalosaurus and given the name Proceratosaurus bradleyi, meaning ‘before Ceratosaurus (‘horned lizard’)', because it was thought to be the ancestor of Ceratosaurus based on the similar horn like crest it had on it’s snout.
Now, the latest research suggests that Proceratosaurus was in fact a primitive coelurosaur (the family that contains tyrannosaurs and ‘raptors’ among others).
It lived around 165 million years ago in the Mid Jurassic (called the Bathonian), some 100 million years before T.rex and was between 3 and 4 metres long (as opposed to T.rex, which was about 13).
More here.
Fun fact: Proceratosaurus‘ name appears on the embryo storage unit and on the map in the tour car in the first Jurassic Park films. It does not, however, appear in person in any of the films.
About the Author:
Galvasean has an avid interest in dinosaurs and palaeontology.
He moderates, funnily enough, the Palaentology forum on Boards.ie
He’s also a stand up comedian, atheist, science-man and may possibly be Nerins father in some weird Japanimation alternate universe.
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