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]
Slight increase in diversity of cold-tolerant ostracods and foraminifers, along with major extinctions of gastropods, reptiles, amphibians, and multituberculate mammals. Many modern mammal groups begin to appear: first glyptodonts, ground sloths, canids, peccaries, and the first eagles and hawks. Diversity in toothed and baleen whales. 33 Ma
The evolution of color vision in primates is highly unusual compared to most eutherian mammals. A remote vertebrate ancestor of primates possessed tetrachromacy , [ 1 ] but nocturnal , warm-blooded , mammalian ancestors lost two of four cones in the retina at the time of dinosaurs .
Lissamphibia (extant amphibians) retain many features of early amphibians but they have only four digits (caecilians have none). 330-300 Ma Hylonomus. From amphibians came the first amniotes: Hylonomus, a primitive reptile, is the earliest amniote known.
Today, most mammals possess dichromatic vision, corresponding to protanopia red–green color blindness. They can thus see violet, blue, green and yellow light, but cannot see ultraviolet or deep red light. [5] [6] This was probably a feature of the first mammalian ancestors, which were likely small, nocturnal, and burrowing.
Phylogenetic tree of the primates Notharctus. The evolutionary history of the primates can be traced back 57-90 million years. [1] One of the oldest known primate-like mammal species, Plesiadapis, came from North America; [2] another, Archicebus, came from China. [3]
The evolution of color vision in primates is unique among most eutherian mammals. While the remote vertebrate ancestors of the primates possessed three color vision (trichromaticism), the nocturnal , warm-blooded , mammalian ancestors lost one of three cones in the retina during the Mesozoic era.
The evolution of tetrapods began about 400 million years ago in the Devonian Period with the earliest tetrapods evolved from lobe-finned fishes. [1] Tetrapods (under the apomorphy-based definition used on this page) are categorized as animals in the biological superclass Tetrapoda, which includes all living and extinct amphibians, reptiles, birds, and mammals.