Carnivore
 |
||||
Dinosaur Eras and Eons (periods) |
||||
 |
 |
 |
||
Dinosaurs |
||||
 |
 |
 |
 |
 |
 |
 |
|||
Dinosaurs Food Sources |
||||
 |
 |
 |
||
Carnivore
A carnivore meaning 'meat eater' (Latin carne meaning 'flesh' and vorare meaning 'to devour'), is an animal with a diet consisting mainly of meat, whether it comes from animals living or dead (scavenging). Some animals are considered carnivores even if their diets contain very little meat but involve preying on other animals (e.g., predatory arthropods such as spiders or mantids that may rarely consume small vertebrate prey). Animals that subsist on a diet consisting only of meat are referred to as obligate carnivores. Plants that capture and digest insects are called carnivorous plants. Similarly fungi that capture microscopic animals are often called carnivorous fungi. The term hypercarnivore is used for an animal that exclusively eats meat and nothing else.
Carnivores that eat insects and similar invertebrates primarily or exclusively are called insectivores, while those that eat fish primarily or exclusively are called piscivores. Carnivory that entails the consumption of members of an organism's own species is referred to as cannibalism. This includes sexual cannibalism and cannibalistic infanticide.
The word "carnivore" sometimes refers to the mammals of the Order Carnivora, but this can be misleading. Although many Carnivora fit the first definition of being exclusively meat eaters, not all do. For example, bears are members of Carnivora that are not carnivores in the dietary sense.
There are also several genera containing carnivorous plants, and several phyla containing carnivorous fungi. The former are predominantly insectivores, while the latter prey mostly on microscopic invertebrates such as nematodes, amoeba and springtails.
Prehistoric mammals of the crown-clade Carnivoramorpha (Carnivora and Miacoidea without Creodonta), along with the early Order Creodonta, and some mammals of the even early Order Cimolesta, were true carnivores. The earliest carnivorous mammal is considered to be the Cimolestes that existed during the Late Cretaceous and Tertiary Periods in North America about 65 million years ago. Most species of Cimolestes were mouse to rat-sized, but the Late Cretaceous Cimolestes magnus reached the size of a marmot, making it one of the largest Mesozoic mammals known (20-60g). The cheek teeth combined the functions of piercing, shearing and grinding, and the molars of Palaeoryctes had extremely high and acute cusps that had little function other than piercing. The dentition of Cimolestes foreshadows the same cutting structures seen in all later carnivores. While the earlier smaller species were insectivores, the later marmot-sized Cimolestes magnus probably took larger prey and were definitely a carnivore to some degree. The cheek teeth of Hyracolestes ermineus (an ermine-like shrew - 40g) and Sarcodon pygmaeus ("pygmy flesh tooth" - 75g), were common in the Latest Paleocene of Mongolia and China and occupied the small predator niche. The cheek teeth show the same characteristic notches that serve in today's carnivores to hold flesh in place to shear apart with cutting ridges. The theropod dinosaurs such as Tyrannosaurus rex that existed during the late Cretaceous, although not mammals were obligate carnivores.