Thursday, 29 September 2016
Monday, 26 September 2016
SAUROPTERYGIANS
The sauropterygians are a group of diverse extinct aquatic marine reptiles that developed from terrestrial ancestors soon after the end Permian extinction. We see their earliest rellies about 245 million years ago, during the Triassic.
Their oldest relatives were small, semi-aquatic reptiles with four limbs that were adapted for paddling around in shallow water. By the end of the Triassic, they had grown to much larger animals fully adapted to a life at sea and were incapable of coming to shore.
Throughout the Jurassic and the Cretaceous developed a diverse range of body plans adapted for a life in the water. They went extinct at the end of the Cretaceous along with the dinosaurs.
The best known of the sauropterygians are the long neck Plesiosaurs but this taxon includes a whole host of other interesting Mesozoic marine reptiles. then flourished during the Mesozoic.
Sauropterygians are united by a radical adaptation of their pectoral girdle, designed to support powerful flipper strokes. While Tyrannosaurs ruled the land, and flying reptiles ruled the skies, the mighty Mosasaurs dominated the seas. They were late to the aquatic party, being the last clade to evolve. Photo: By Ryan Somma - PlesiosaurusUploaded by FunkMonk, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=6735975
Their oldest relatives were small, semi-aquatic reptiles with four limbs that were adapted for paddling around in shallow water. By the end of the Triassic, they had grown to much larger animals fully adapted to a life at sea and were incapable of coming to shore.
Throughout the Jurassic and the Cretaceous developed a diverse range of body plans adapted for a life in the water. They went extinct at the end of the Cretaceous along with the dinosaurs.
The best known of the sauropterygians are the long neck Plesiosaurs but this taxon includes a whole host of other interesting Mesozoic marine reptiles. then flourished during the Mesozoic.
Sauropterygians are united by a radical adaptation of their pectoral girdle, designed to support powerful flipper strokes. While Tyrannosaurs ruled the land, and flying reptiles ruled the skies, the mighty Mosasaurs dominated the seas. They were late to the aquatic party, being the last clade to evolve. Photo: By Ryan Somma - PlesiosaurusUploaded by FunkMonk, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=6735975
Friday, 9 September 2016
Wednesday, 7 September 2016
Sunday, 4 September 2016
BRITISH COLUMBIA'S GREAT BEARS
Hiking in BC, both grizzly and black bear sightings are common. Nearly half the world's population, some 25,000 grizzlies, roam the Canadian wilderness. This photo of Edward (yes, we named him) was taken off the west coast of Vancouver Island by Larissa Harding of Great Bear Nature Tours.
Both bear families descend from a common ancestor, Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Seems an implausible lineage given the size of their very large descendents.
An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head. It is one of the largest grizzly bears ever recorded. This past month this king of the forest was seen once again in the Washington Cascades -- the first sighting in 50 years.
Both bear families descend from a common ancestor, Ursavus, a bear-dog the size of a raccoon who lived more than 20 million years ago. Seems an implausible lineage given the size of their very large descendents.
An average Grizzly weighs in around 800 lbs (363 kg), but a recent find in Alaska tops the charts at 1600 lbs (726 kg). This mighty beast stood 12' 6' high at the shoulder, 14' to the top of his head. It is one of the largest grizzly bears ever recorded. This past month this king of the forest was seen once again in the Washington Cascades -- the first sighting in 50 years.
Friday, 2 September 2016
TORVOSAURUS TANNERI
The genus Torvosaurus includes a unique species of megalosaurid therapod dinosaur.
This fellow is from the Morrison Formation, western United States but his kind spread widely and fossil specimens of the same species have been found in the Lourinha Formation near Lisbon, Portugal. He is currently on display at the Museo Nacional De Ciencias Naturales in Madrid, Spain.
Torvosaurus were one of the largest and most robust carnivores of the Jurassic. These "savage lizards" were true to their name. Skilled hunters, who could grow from 9 to ll meters long, weigh over 2 tons, were bipedal with powerful dentition and strong claws on their forelegs, they ruled the Upper Jurassic.
While currently speculative, there seems to be a high likelihood that these bad boys hunted and dined upon the big sauropods of their time.