Stellers sea cow (Hydrodamalis gigas) is a an extinct sirenian described by Georg Wilhelm Steller in 1741. Most of what we know about Steller’s sea cow comes from Steller's observations. It belonged to the order Sirenia and the family Dugongidae, of which the dugong (Dugong … [Read more...]
Extinct is a classification category on the International Union for the Conservation of Nature’s (IUCN) Threatened Species List.
Extinction occurs when a species — also called “taxon” for the list — no longer exists anywhere on earth.
When scientists have done extensive research and agree that there is no longer a single individual specimen of the species they declare it extinct. Essentially, extinction represents the termination of a taxon.
There are six main reasons why species become extinct:
- Habitat loss
- Introduction of a foreign species
- Loss of genetic variation
Conservation Status List
- Extinct in the Wild
- Critically Endangered
- Near Threatened
- Least Concern
- Data Deficient
- Not Evaluated
PHYSICAL DESCRIPTION The protoceratops was one of the smaller dinosaurs. They were about 3 feet tall and roughly 7 feet wide. They walked on four legs, which were all the same size. They had frills at the back of their neck. The protoceratops was a roughly light dinosaur at … [Read more...]
PHYSICAL DESCRIPTION Pachycephalosaurus are most widely known for their very thick skull roof. The bone on top of its head was close to ten inches thick, and was probably used for defense. Pachycephalosaurus would probably use the top of their head much like a modern day ram … [Read more...]
PHYSICAL DESCRIPTION The plesiosaurus was one of the largest aquatic animals and lived throughout the cretaceous period). It grew up to twenty three meters long, making it among some of the largest sea creatures. Like other sauropterygians it was a very successful reptile that … [Read more...]
The Allosaurus has a name that literally means the other lizard. Possibly this was due to the fact that the first bones were discovered during the bone wars between Edward Cope and Othniel Marsh during the late 19th century in Wyoming and Colorado. What started as competition for … [Read more...]
PHYSICAL DESCRIPTION The defining point of an ankylosaurus is its armor. Their armor consists of very tough bones and scales embedded in its skin. They were a very large animal. Ankylosauruses could be up to 30 feet long, 6 feet wide, and about 4 feet high. Most animals today are … [Read more...]
PHYSICAL DESCRIPTION The Apatosaurus is the new name for Brontosaurus (which is this dinosaur’s popular title and the one that most people will know it by). At most the Apatosaurus could only hold its head up about 17 feet off the ground. However, the Apatosaurus was 70 feet … [Read more...]
PHYSICAL DESCRIPTION The Brachiosaurus was the largest, heaviest, and among the least inteligent dinosaurs found to date. This massive dinosaur could weigh anywhere between a staggering 60 thousand to an unbelievable over 170 thousand pounds (That is roughly 48 mid sized cars). … [Read more...]
The Dilophosaurus was a flesh eating dinosaur that lived in North America and China about 193 million years ago, during the Sinemurian stage of the Early Jurassic Period.Its name refers to twin crests that adorn the skull of this ancient reptile; “two crested lizard”; derived … [Read more...]
PHYSICAL DESCRIPTION The Dimetrodon resembled much of what people would misclassify as a “dinosaur”, however it lived during the Permian period (about 260 million years ago) which is before most dinosaurs. It was about nine feet long, and had legs that were on the side of its … [Read more...]