Editing Cretaceous (section)

==Terrestrial fauna==
On land, [[mammal]]s were generally small sized, but a very relevant component of the [[Fauna (animals)|fauna]], with [[cimolodont]] [[multituberculates]] outnumbering dinosaurs in some sites.<ref>{{cite book |last1=Kielan-Jaworowska |first1=Zofia |first2=Richard L. |last2=Cifelli |first3=Zhe-Xi |last3=Luo|year=2005 |title=Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure |url=https://archive.org/details/mammalsfromagedi00kiel_769 |url-access=limited |page=[https://archive.org/details/mammalsfromagedi00kiel_769/page/n317 299] |publisher=Columbia University Press |isbn=9780231119184}}</ref> Neither true [[marsupial]]s nor [[placental]]s existed until the very end,<ref>{{cite journal |last1=Halliday |first1=Thomas John Dixon |last2=Upchurch |first2=Paul |last3=Goswami |first3=Anjali |date=29 June 2016 |title=Eutherians experienced elevated evolutionary rates in the immediate aftermath of the Cretaceous–Palaeogene mass extinction |journal=[[Proceedings of the Royal Society B]] |volume=283 |issue=1833 |pages=20153026 |doi=10.1098/rspb.2015.3026 |pmc=4936024 |pmid=27358361 }}</ref> but a variety of non-marsupial [[metatheria]]ns and non-placental [[eutherian]]s had already begun to diversify greatly, ranging as carnivores ([[Deltatheroida]]), aquatic foragers ([[Stagodontidae]]) and herbivores (''[[Schowalteria]]'', [[Zhelestidae]]). Various "archaic" groups like [[eutriconodont]]s were common in the Early Cretaceous, but by the Late Cretaceous northern mammalian faunas were dominated by multituberculates and [[theria]]ns, with [[dryolestoid]]s dominating [[South America]].

The [[apex predator]]s were [[archosaur]]ian [[reptile]]s, especially [[dinosaur]]s, which were at their most diverse stage. Avians such as the ancestors of modern-day [[birds]] also diversified. They inhabited every continent, and were even found in cold polar latitudes. [[Pterosaur]]s were common in the early and middle Cretaceous, but as the Cretaceous proceeded they declined for poorly understood reasons (once thought to be due to competition with early [[bird]]s, but now it is understood avian [[adaptive radiation]] is not consistent with pterosaur decline<ref>{{Cite book| title = Pterosaurs: Natural History, Evolution, Anatomy|author=Wilton, Mark P. |isbn=978-0691150611|year=2013|publisher=Princeton University Press }}</ref>). By the end of the period only three highly specialized [[Family (biology)|families]] remained; [[Pteranodontidae]], [[Nyctosauridae]], and [[Azhdarchidae]].<ref>{{Cite journal|last1=Longrich|first1=Nicholas R.|last2=Martill|first2=David M.|last3=Andres|first3=Brian|date=2018-03-13|title=Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary|journal=PLOS Biology|language=en|volume=16|issue=3|pages=e2001663|doi=10.1371/journal.pbio.2001663|issn=1545-7885|pmc=5849296|pmid=29534059 |doi-access=free }}</ref>

The [[Liaoning]] [[lagerstätte]] ([[Yixian Formation]]) in China is an important site, full of preserved remains of numerous types of small dinosaurs, birds and mammals, that provides a glimpse of life in the Early Cretaceous. The [[coelurosaur]] dinosaurs found there represent types of the group [[Maniraptora]], which includes modern birds and their closest non-avian relatives, such as [[dromaeosaurs]], [[oviraptorosaurs]], [[therizinosaurs]], [[troodontids]] along with other [[avialans]]. Fossils of these dinosaurs from the [[Liaoning]] [[lagerstätte]] are notable for the presence of hair-like [[feather]]s.

[[Insect]]s diversified during the Cretaceous, and the oldest known [[ant]]s, [[termite]]s and some [[lepidoptera]]ns, akin to [[Butterfly|butterflies]] and [[moth]]s, appeared. [[Aphid]]s, [[grasshopper]]s and [[gall wasp]]s appeared.<ref name="UCMP" />
<gallery class="center">
File:Tyrannosaurus-rex-Profile-steveoc86.png|''[[Tyrannosaurus|Tyrannosaurus rex]]'', one of the largest land predators of all time, lived during the Late Cretaceous
File: Velociraptor Restoration.png|Up to 2 m long and 0.5 m high at the hip, ''[[Velociraptor]]'' was feathered and roamed the Late Cretaceous
File: Triceratops by Tom Patker.png|''[[Triceratops]]'', one of the most recognizable genera of the Cretaceous
File:Quetzalcoatlus07.jpg|The [[azhdarchid]] ''[[Quetzalcoatlus]]'', one of the largest animals to ever fly, lived during the Late Cretaceous
File:Confuciusornis sanctus mmartyniuk.png|''[[Confuciusornis]]'', a genus of crow-sized birds from the Early Cretaceous
File:Ichthyornis restoration.jpeg|''[[Ichthyornis]]'' was a toothed, [[seabird]]-like [[ornithuran]] from the Late Cretaceous
</gallery>

=== Rhynchocephalians ===
[[File:Priosphenodon_skeleton.png|thumb|Skeleton of ''[[Priosphenodon|Priosphenodon avelasi]]'' a large herbivorous rhynchocephalian known from the mid-Cretaceous of South America]][[Rhynchocephalia]]ns (which today only includes the [[tuatara]]) disappeared from North America and Europe after the [[Early Cretaceous]],<ref name="Cleary-2018">{{cite journal|vauthors=Cleary TJ, Benson RB, Evans SE, Barrett PM|date=March 2018|title=Lepidosaurian diversity in the Mesozoic-Palaeogene: the potential roles of sampling biases and environmental drivers|journal=Royal Society Open Science|volume=5|issue=3|pages=171830|bibcode=2018RSOS....571830C|doi=10.1098/rsos.171830|pmc=5882712|pmid=29657788}}</ref> and were absent from North Africa<ref name="Apesteguía-2016">{{cite journal|vauthors=Apesteguía S, Daza JD, Simões TR, Rage JC|date=September 2016|title=The first iguanian lizard from the Mesozoic of Africa|journal=Royal Society Open Science|volume=3|issue=9|pages=160462|bibcode=2016RSOS....360462A|doi=10.1098/rsos.160462|pmc=5043327|pmid=27703708}}</ref> and northern South America<ref>{{cite journal|vauthors=Simões TR, Wilner E, Caldwell MW, Weinschütz LC, Kellner AW|date=August 2015|title=A stem acrodontan lizard in the Cretaceous of Brazil revises early lizard evolution in Gondwana|journal=[[Nature Communications]]|volume=6|issue=1|pages=8149|bibcode=2015NatCo...6.8149S|doi=10.1038/ncomms9149|pmc=4560825|pmid=26306778}}</ref> by the early [[Late Cretaceous]]. The cause of the decline of Rhynchocephalia remains unclear, but has often been suggested to be due to competition with advanced lizards and mammals.<ref name="Jones-2009">{{cite journal|vauthors=Jones ME, Tennyson AJ, Worthy JP, Evans SE, Worthy TH|date=April 2009|title=A sphenodontine (Rhynchocephalia) from the Miocene of New Zealand and palaeobiogeography of the tuatara (Sphenodon)|journal=Proceedings. Biological Sciences|volume=276|issue=1660|pages=1385–90|doi=10.1098/rspb.2008.1785|pmc=2660973|pmid=19203920}}</ref> They appear to have remained diverse in high-latitude southern South America during the Late Cretaceous, where lizards remained rare, with their remains outnumbering terrestrial lizards 200:1.<ref name="Apesteguía-2016" />

=== Choristodera ===
[[File:Philydrosaurus proseilus NMNS.jpg|thumb|''[[Philydrosaurus]]'', a choristodere from the Early Cretaceous of China]]
[[Choristodera|Choristoderes]], a group of freshwater aquatic reptiles that first appeared during the preceding Jurassic, underwent a major [[evolutionary radiation]] in Asia during the Early Cretaceous, which represents the high point of choristoderan diversity, including long necked forms such as ''[[Hyphalosaurus]]'' and the first records of the gharial-like [[Neochoristodera]], which appear to have evolved in the regional absence of aquatic [[neosuchia]]n crocodyliformes. During the Late Cretaceous the neochoristodere ''[[Champsosaurus]]'' was widely distributed across western North America.<ref name="Matsumoto-2010">{{cite journal|vauthors=Matsumoto R, Evans SE|year=2010|title=Choristoderes and the freshwater assemblages of Laurasia|journal=[[Journal of Iberian Geology]]|volume=36|issue=2|pages=253–274|doi=10.5209/rev_jige.2010.v36.n2.11|bibcode=2010JIbG...36..253M |doi-access=free}}</ref> Due to the extreme climatic warmth in the Arctic, choristoderans were able to colonise it too during the Late Cretaceous.<ref name="LateCretaceousArcticVertebrates" />