Showing posts with label predator. Show all posts
Showing posts with label predator. Show all posts

Friday, March 22, 2024

MIGHTY EAGLE: KWIKW (KW-EE-KW)

Bald Eagle / Kwikw / Haliaeetus leucocephalus
A mighty Bald Eagle sitting with wings spread looks to be controlling the weather with his will as much as being subject to it. 

This fellow has just taken a dip for his evening meal and is drying his feathers in the wind. 

As you can imagine, waterlogged feathers make flight difficult. Their wings are built for graceful soaring and gliding on updrafts of warm air called thermals. 

Their long feathers are slotted, easily separating so air flows smoothly and giving them the added benefit of soaring at slower speeds. 

As well as his wings, this fellow is also drying off his white head feathers. A bald eagle's white head can make it look bald from a distance but that is not where the name comes from. It is from the old English word balde, meaning white.

In the Kwak'wala language of the Kwakiutl First Nations of the Pacific Northwest — or Kwakwaka'wakw, speakers of Kwak'wala — an eagle is known as kwikw (kw-ee-kw) and an eagle's nest is called a kwigwat̕si

Should you encounter an eagle and wish to greet them in Kwak'wala, you would just say yo. Yup, just yo. They would like your yo hello better if you offered them some fresh fish. They dine on all sorts of small mammals, fish and birds but are especially fond of pink salmon or ha̱nu'n (han-oon).

These living dinosaurs are a true homage to their lineage. They soar our skies with effortless grace. Agile, violent and beautiful, these highly specialized predators can catch falling prey mid-flight and dive-bomb into rivers to snag delicious salmon. 

Their beauty and agility are millions of years in the making. From their skeletal structure to their blood cells, today’s birds share a surprising evolutionary foundation with reptiles. 

Between 144 million and 66 million years ago, during the Mesozoic era, we see the first birds evolve. Eventually, tens of millions of years ago, an ancient group of birds called kites developed. Like today’s bald eagle, early kites are thought to have scavenged and hunted fish.

About 36 million years ago, the first eagles descended from kites, their smaller cousins. First to appear were the early sea eagles, which — like kites — continued to prey on fish and whose feet were free of feathers, along with booted eagles, which had feathers below the knee. Fossils of Bald Eagles are very rare and date to the late Pleistocene. Eagles are known from the early Pleistocene of Florida, but they are extinct species not closely related to the bald eagle.

Like the kites, bald eagles have featherless feet, but they also developed a range of other impressive adaptations that help them hunt fish and fowl in a watery environment. Each foot has four powerful toes with sharp talons. Tiny projections on the bottom of their feet called “spicules” help bald eagles grasp their prey. A bald eagle also has serrations on the roof of its mouth that help it hold slippery fish, and incredibly, the black pigment in its wing feathers strengthens them against breakage when they dive head first into water.

Obviously, there is much more than their striking white heads that sets these iconic raptors apart from the crowd. Their incredible physiology, built for life near the water, is literally millions of years in the making. 

Tuesday, August 30, 2022

SPINOSAURUS AEGYPTIACUS

Spinosaurus the Spine Lizard of the Cretaceous
This beautiful big boy painted in yellow, green and blue is Spinosaurus aegyptiacus. 

Spinosaurus (meaning "spine lizard") is a genus of spinosaurid dinosaur that lived in what now is North Africa during the Cenomanian to upper Turonian in the Late Cretaceous— 99 to 93.5 million years ago. 

The genus was known first from Egyptian remains discovered in 1912 and described by German palaeontologist Ernst Stromer in 1915. 

The original remains were destroyed in World War II, but additional material came to light in the early 21st century.  It is unclear whether one or two species are represented in the fossils reported in the scientific literature. The best known species is S. aegyptiacus from Egypt, although a potential second species, S. maroccanus, has been recovered from Morocco. The contemporary spinosaurid genus Sigilmassasaurus has also been synonymized by some authors with S. aegyptiacus, though other researchers propose it to be a distinct taxon. 

In 2014, Ibrahim and his colleagues suggested that Spinosaurus aegyptiacus could reach over 15 metres (49 ft) in length. In 2022, however, Paul Sereno and his colleagues suggested that Spinosaurus aegyptiacus reached a maximum body length of 14 metres (46 ft) and a maximum body mass of 7.4 metric tons (8.2 short tons) by constructing an adult flesh model "with the axial column in neutral pose."

Spinosaurus is the longest known terrestrial carnivore; other large carnivores comparable to Spinosaurus include theropods such as Tyrannosaurus, Giganotosaurus and Carcharodontosaurus. The most recent study suggests that previous body size estimates are overestimated, and that S. aegyptiacus reached 14 metres (46 ft) in length and 7.4 metric tons (8.2 short tons) in body mass. 

The skull of Spinosaurus was long, low, and narrow, similar to that of a modern crocodilian, and bore straight conical teeth with no serrations. It would have had large, robust forelimbs bearing three-fingered hands, with an enlarged claw on the first digit. The distinctive neural spines of Spinosaurus, which were long extensions of the vertebrae (or backbones), grew to at least 1.65 meters (5.4 ft) long and were likely to have had skin connecting them, forming a sail-like structure, although some have suggested that the spines were covered in fat to form hump.

Saturday, January 22, 2022

CANADA'S FIRST SABRE-TOOTHED CAT: SMILODON

This fierce predator with the luxurious coat is Smilodon fatalis — a compact but robust killer that weighed in around 160 to 280 kg and was 1.5 - 2.2 metres long.

Smilodon is a genus of the extinct machairodont subfamily of the felids. It is one of the most famous prehistoric mammals and the best known saber-toothed cat. Although commonly known as the saber-toothed tiger, it was not closely related to the tiger or other modern cats.

Up until a few years ago, all the great fossil specimens of this apex predator were found south of us in the United States. That was until some interesting bones from Medicine Hat, Alberta got a second look.

A few years ago, a fossil specimen caught the eye of researcher Ashley Reynolds as she was rummaging through the collections at the Royal Ontario Museum in Toronto. 

Back in the 1960s,  University of Toronto palaeontologist C.S. Churcher and his team had collected and donated more than 1,200 specimens from their many field seasons scouring the bluffs of the South Saskatchewan River near Medicine Hat, Alberta.

Churcher is a delightful storyteller and a palaeontologist with a keen eye. I had the very great pleasure of listening to many of his talks out at the University of British Columbia and a few Vancouver Paleontological Society meetings in the mid-2000s. 

"Rufus" was a thoroughly charming storyteller and shared many of his adventures from the field. 

He moved out to the West Coast for his retirement, first to Gabriola Island then to Victoria, but his keen love of the science kept him giving talks to enthralled listeners keen to hear about his survey of the Dakhleh Oasis in the Western Desert of Egypt, geomorphology, stratigraphy, recent biology, Pleistocene and Holocene lithic cultures, insights learned from Neolithic Islamic pottery to Roman settlements.

The specimens he had collected had been roughly sorted but never examined in detail. Reynolds, who was researching the growth patterns and life histories of extinct cats saw a familiar-looking bone from an ancient cat's right front paw. That tiny paw bone had reached through time and was positively identified as Canada's first Smilodon.

These Apex Predators used their exceptionally long upper canine teeth to hunt large mammals. 

Isotopes preserved in the bones of S. fatalis in the La Brea Tar Pits in California tell us that they liked to dine on bison (Bison antiquus) and camels (Camelops) along with deer and tapirs. Smilodon is thought to have killed its prey by holding it still with its forelimbs and biting it. And that was quite the bite!

Their razor-sharp incisors were arranged in an arch. Once they bit down, the teeth would hold their prey still and stabilize it while the canine bite was delivered — and what a bite that was. They could open their mouths a full 120 degrees.

Smilodon died out at the same time that most North and South American megafauna disappeared, about 10,000 years ago. Its reliance on large animals has been proposed as the cause of its extinction, along with climate change and competition with other species.