Monday, 31 December 2007
CARCHARDONTOSAURUS GOES EXTINCT TWICE
Tooth fragments collected by Charles Depéret and J. Savornin in 1927 were misplaced before this meat-eater could ever be described and when additional material was collected in Egypt in the 1930’s it also came to an unfortunate end. Sent to German paleontologists in Munich to describe, the fossils were lost in the rubble as Allied Forces bombed the building in which they were housed during WW II.
But the rocky history and luck of Carcharodontosaurus iguidensis improved when paleontologist Paul Sereno found cranial material on a Moroccan dig in 1996. That find combined with material collected the following year in Nigeria were examined by Sereno and Steve Brusatte, a paleobiologist at the University of Bristol in England, and Paul Sereno and determined to be a new species, not C. saharicus as originally thought.
The massive skull, neck and bone fragments belonged to Carcharodontosaurus iguidensis, one of the largest dinosaurs ever found. Carcharodontosaurus differs from C. saharicus, his smaller Saharan coursin, both in the maxilla and braincase. Carcharodontosaurus iguidensis walked upright and was a massive beast, weighing in at an impressive 3.2 tons.
Extending upwards of 14 meters (44 ft), nearly as long as Tyrannosaurs, alive today they could easily peer through a second story window - a menacing thought as they were well-equipped hunters with sizable teeth.The climate was much warmer when Carcharodontosaurus iguidensis and C. saharicus roamed the Earth and the seas much higher. Beyond geographic distance, the raised sea level may have been what set these therapods apart. Shallow seas separated what is now Morocco and Nigeria and this separation may have prompted the development of the unique characteristics define the two species.. Perhaps more abundant prey and favorable conditions allowed Carcharodontosaurus iguidensis to grow to their huge size while C. saharicus remained a smallish 1.6 meters (5.2 ft).
While not a reptile, C. saharicus has been compared with modern Crocodylia, another group who first appeared in the Cretaceous, as they share similar inner ear anatomy and cerebrum size relative to total brain. Like many therapods prior to the 1930’s, the African species were originally misgrouped into the genus Megalosaurus. Paleontologist Ernst Stromer von Reichenbach corrected this error.
After taking a closer look at their anatomy, particularly their dentition, he renamed them Carcharodontosaurus in 1931 citeing their "mainly Carcharodon-like teeth", which were "not recurved, almost bilaterally symmetrical but with convex edges” The Carcharodontosaurids were a group of gigantic carnivorous carcharodontosaurid dinosaurs that lived 98 to 93 million years ago.
Carcharodontosaurus means 'shark lizard', after the shark genus Carcharodon, an apt handle as they were ominous killers with enormous jaws and long, serrated teeth, some as long as eight inches.
Thursday, 27 December 2007
Fossil Field Trip to the Olympic Peninsula
Tuesday, 18 December 2007
While rare today, these are British Columbia’s only native oyster. Had you been dining on their brethren in the 1800s or earlier, it would have been this species you were consuming. Middens from Port Hardy to California are built from Ostrea lurida.
These wonderful invertebrates bare their souls with every bite. Have they lived in cold water, deep beneath the sea away from the suns rays and heat? Are they the rough and tumbled beach denizens whose thick shells have formed to withstand the pounding of the sea?
Is the oyster in your mouth thin and slimy having just done the nasty spurred by the warming waters of Spring? Is this oyster a local or was it shipped to your current local and if asked would greet you with "Kon'nichiwa?" Not if the beauty on your plate is indeed Ostrea lurida.
We have been cultivating, indeed maximizing the influx of invasive species to the cold waters of the Salish Sea. But in the wild waters off the coast of British Columbia is the last natural abundant habitat of the tasty Ostrea lurida in the pristine waters of Nootka Sound. The area is home to the Nuu-chah-nulth First Nations who have consumed this species boiled or steamed for thousands of years. Here these ancient oysters not only survive but thrive — building reefs and providing habitat for crab, anemones and small marine animals.
Oysters are in the family Ostreidae — the true oysters. Their lineage evolved in the Early Triassic — 251 - 247 million years ago.
In the Kwak̓wala language of the Kwakiutl or Kwakwaka'wakw, speakers of Kwak'wala, of the Pacific Northwest, an oyster is known as t̕łox̱t̕łox̱. I am curious to learn if any of the Nuu-chah-nulth have a different word for an oyster. If you happen to know, I would be grateful to learn.