Search results
Results From The WOW.Com Content Network
Archaeoceti ("ancient whales"), or Zeuglodontes in older literature, is a paraphyletic group of primitive cetaceans that lived from the Early Eocene to the late Oligocene 1] Representing the earliest cetacean radiation , they include the initial amphibious stages in cetacean evolution , thus are the ancestors of both modern cetacean suborders ...
Another similar feature was the composition of the teeth, which contained mostly calcium phosphate which is needed for eating and drinking by aquatic animals, though, unlike modern day toothed whales, they had a heterodont (more than one tooth morphology) dentition as opposed to a homodont (one tooth morphology present) dentition. [62]
Outside the upper one-rooted teeth and inside the upper two-rooted teeth there are pits for reception of the lower teeth. [14] Zygorhiza (and Dorudon) replaced their upper and lower deciduous first premolars with permanent teeth. This is very unusual in modern mammals and contrasts to extant toothed whales that only develop a single set of teeth.
This made it possible for whales to move around with the vertical tail hitting the water. The front legs transformed into flippers, costing them their mobility on land. [75] One of the oldest members of ancient cetaceans (Archaeoceti) is Pakicetus from the Middle Eocene of Pakistan. This is an animal the size of a wolf, whose skeleton is known ...
Basilosaurus (meaning "king lizard") is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago (mya). ). First described in 1834, it was the first archaeocete and prehistoric whale known to scienc
Millions of prehistoric marine fossils were discovered beneath a California high school over the course of a multi-year construction project. The relics recovered at San Pedro High School included ...
Ukrainian material is known from sediments containing glauconite, formed at depths between 50–500 m (160–1,640 ft) and most common between 200–300 m (660–980 ft), which has been interpreted to mean that Pachycetus at least occasionally left the shallows to venture into the open ocean. One hypothesis suggests that Pachycetus may have ...
An intact prehistoric mastodon jaw was discovered in the backyard of a Hudson Valley house after the homeowner initially saw a pair of teeth poking up by a plant, according to state officials.