Editing Carnivore (section)

==Prehistory of carnivory==
{{main|Predation#Evolutionary history|Evolutionary history of life}}
''[[Predation]]'' (the eating of one living [[organism]] by another for [[nutrition]]) predates the rise of commonly recognized carnivores by hundreds of millions (perhaps billions) of years. It began with [[single-celled organism]]s that [[phagocytosis|phagocytoze]]d and [[digestion|digest]]ed other cells, and later evolved into [[multicellular organism]]s with [[cell differentiation|specialized cells]] that were dedicated to breaking down other organisms. Incomplete digestion of the prey organisms, some of which survived inside the predators in a form of [[endosymbiosis]], might have led to [[symbiogenesis]] that gave rise to [[eukaryote]]s and eukaryotic [[autotroph]]s such as [[green algae|green]] and [[red algae]].

===Proterozoic origin===
The earliest predators were [[microorganism]]s, which engulfed and "swallowed" other smaller [[cell (biology)|cell]]s (i.e. [[phagocytosis]]) and [[intracellular digestion|digested them internally]]. Because the earliest fossil record is poor, these first predators could date back anywhere between 1 and over 2.7&nbsp;[[bya]] (billion years ago).<ref name=Bengtson-2002-10/>

The rise of [[eukaryotic]] cells at around 2.7&nbsp;bya, the rise of multicellular organisms at about 2&nbsp;bya, and the rise of [[motile]] predators (around 600&nbsp;Mya – 2&nbsp;bya, probably around 1&nbsp;bya) have all been attributed to early predatory behavior, and many very early remains show evidence of boreholes or other markings attributed to small predator species.<ref name=Bengtson-2002-10/>

The sudden disappearance of the [[precambrian]] [[Ediacaran biota]] at the [[end-Ediacaran extinction]], who were mostly bottom-dwelling [[filter feeder]]s and [[grazing (behaviour)|grazer]]s, has been hypothetized to be partly caused by increased predation by newer animals with hardened skeleton and mouthparts.<ref name="Stanley1973">{{Cite journal |last=Stanley |first=S. M. |year=1973 |title=An ecological theory for the sudden origin of multicellular life in the Late Precambrian |journal=PNAS |volume=70 |issue=5 |pages=1486–1489 |pmid=16592084 |doi=10.1073/pnas.70.5.1486 |pmc=433525 |bibcode=1973PNAS...70.1486S |doi-access=free }}</ref>

===Paleozoic===
The degradation of [[seafloor]] [[microbial mat]]s due to the [[Cambrian substrate revolution]] led to increased active predation among animals, likely triggering various [[evolutionary arms race]]s that contributed to the rapid [[genetic divergence|diversification]] during the [[Cambrian explosion]]. [[Radiodont]] [[arthropod]]s, which produced the first [[apex predator]]s such as ''[[Anomalocaris]]'', quickly became the dominant carnivores of the Cambrian sea. After their decline due to the [[Cambrian-Ordovician extinction event]], the niches of large carnivores were taken over by [[nautiloid]] [[cephalopod]]s such as ''[[Cameroceras]]'' and later [[eurypterid]]s such as ''[[Jaekelopterus]]'' during the [[Ordovician]] and [[Silurian]] periods.

The first [[vertebrate]] carnivores appeared after the [[evolution of fish|evolution]] of [[jawed fish]], especially [[armour (zoology)|armor]]ed [[placoderm]]s such as the massive ''[[Dunkleosteus]]''. The dominance of placoderms in the [[Devonian]] ocean forced other fish to venture into other niches, and one clade of [[bony fish]], the [[lobe-finned fish]], became the dominant carnivores of [[freshwater]] [[wetland]]s formed by early [[land plant]]s. Some of these fish became better adapted for breathing air and eventually giving rise to [[amphibian]] [[tetrapod]]s. These early tetrapods were large [[semi-aquatic]] [[piscivores]] and [[riparian]] [[ambush predator]]s that hunt [[terrestrial animal|terrestrial]] arthropods (mainly [[arachnid]]s and [[myriopod]]s), and one group in particular, the [[temnospondyl]]s, became terrestrial apex predators that hunt other tetrapods.<ref name=Sahney-Benton-Ferry-2010/>

The dominance of temnospondyls around the wetland habitats throughout the [[Carboniferous]] forced other amphibians to evolve into [[amniote]]s that had adaptations that allowed them to live farther away from water bodies. These amniotes began to evolve both carnivory, which was a natural transition from insectivory requiring minimal adaptation; and [[herbivory]], which took advantage of the abundance of [[coal forest]] [[foliage]] but in contrast required a complex set of adaptations that was necessary for digesting on the [[cellulose]]- and [[lignin]]-rich plant materials.<ref name=Sahney-Benton-Ferry-2010/> After the [[Carboniferous rainforest collapse]], both [[synapsid]] and [[sauropsid]] amniotes quickly gained dominance as the top terrestrial animals during the subsequent [[Permian]] period. Some scientists assert that [[sphenacodontoid]] synapsids such as ''[[Dimetrodon]]'' "were the first terrestrial vertebrate to develop the curved, serrated teeth that enable a predator to eat prey much larger than itself".<ref name=Foley-2014-02-07/>

===Mesozoic===
In the [[Mesozoic]], some [[theropod]] [[dinosaur]]s such as ''[[Tyrannosaurus|Tyrannosaurus rex]]'' are thought probably to have been obligate carnivores.

Though the theropods were the larger carnivores, several carnivorous mammal groups were already present. Most notable are the [[Gobiconodontidae|gobiconodontids]], the [[Triconodontidae|triconodontid]] ''[[Jugulator (mammal)|Jugulator]]'', the [[Deltatheroida|deltatheroidans]] and ''[[Cimolestes]]''. Many of these, such as ''[[Repenomamus]]'', ''Jugulator'' and ''Cimolestes'', were among the largest mammals in their faunal assemblages, capable of attacking dinosaurs.<ref name=Zofia-Cifelli-Luo-2004/><ref name=Fox-2015/><ref name=Cifelli-Madsen-1998/>

===Cenozoic===
In the early-to-mid-Cenozoic, the dominant predator forms were mammals: [[Hyaenodonta|hyaenodonts]], [[Oxyaenidae|oxyaenids]], [[entelodont]]s, [[ptolemaiida]]ns, [[Arctocyonidae|arctocyonids]] and [[mesonychia]]ns, representing a great diversity of [[eutheria]]n carnivores in the northern continents and [[Africa]]. In [[South America]], [[Sparassodonta|sparassodonts]] were dominant, while [[Australia]] saw the presence of several [[marsupial]] predators, such as the [[Dasyuromorphia|dasyuromorphs]] and [[Thylacoleonidae|thylacoleonids]]. From the [[Miocene]] to the present, the dominant carnivorous mammals have been [[Carnivoramorpha|carnivoramorphs]].

Most carnivorous mammals, from [[dog]]s to ''[[deltatheridium]]s'', share several dental adaptations, such as [[carnassial]] teeth, long [[canine tooth|canine]]s and even similar tooth replacement patterns.<ref name=deMuizon-LangeBadré-1997/> Most aberrant are [[Thylacoleonidae|thylacoleonids]], with a diprodontan dentition completely unlike that of any other mammal; and [[eutriconodonts]] like gobiconodontids and ''Jugulator'', with a three-cusp anatomy which nevertheless functioned similarly to carnassials.<ref name=Zofia-Cifelli-Luo-2004/><ref name=quecome-2017-02-02/>