Search results
Results from the WOW.Com Content Network
The evolution of the digestive system has formed a significant influence in mammal evolution. With the emergence of mammals, the digestive system was modified in a variety of ways depending on the animal's diet. For example, cats and most carnivores have simple large intestines, while the horse as a herbivore has a voluminous large intestine. [127]
Ceratopsian dinosaurs appear in the fossil record and the oldest known eutherian mammal: Juramaia. 160 Ma Multituberculate mammals (genus Rugosodon) appear in eastern China. 155 Ma First blood-sucking insects (ceratopogonids), rudist bivalves, and cheilostome bryozoans.
After the K–Pg extinction, mammals evolved to fill the niches left vacant by the dinosaurs. [ 154 ] [ 155 ] Some research indicates that mammals did not explosively diversify across the K–Pg boundary, despite the ecological niches made available by the extinction of dinosaurs. [ 156 ]
During the Early Cretaceous, new dinosaurs evolved to replace the old ones. Sauropods were still present, but they were not as diverse as they were in the Jurassic Period. Theropods from the Early Cretaceous of North America include dromaeosaurids such as Deinonychus and Utahraptor, the carnosaur Acrocanthosaurus, and the coelurosaur Microvenator.
“Some of the earliest mammals were forced to live toward the bottom of the food chain and have likely spent 100 million years during the age of the dinosaurs evolving to survive through rapid ...
The Mesozoic era followed and the dinosaurs began their rise to dominance, spreading into the country before Pangaea split up. During the latter Jurassic Morrison Formation dinosaurs lived in the western states. During the Cretaceous, the Gulf of Mexico expanded until it split North America in half. Plesiosaurs and mosasaurs swam in its waters.
Miacidae ("small points") is a former paraphyletic family of extinct primitive placental mammals that lived in North America, Europe and Asia during the Paleocene and Eocene epochs, about 65–33.9 million years ago.
“Some of the earliest mammals were forced to live toward the bottom of the food chain and have likely spent 100 million years during the age of the dinosaurs evolving to survive through rapid ...