Editing Cenozoic (section)

==Life==
[[File:Paleotherium magnum.jpg|thumb|left|Restoration of ''[[Palaeotherium]]'', a [[Paleogene]] relative of horses that lived in subtropical climates of Europe during the [[Eocene]]]]
Early in the Cenozoic, following the [[Cretaceous-Paleogene Extinction Event|K-Pg event]], the planet was dominated by relatively small fauna, including small mammals, birds, reptiles, and amphibians. From a geological perspective, it did not take long for mammals to greatly diversify in the absence of the dinosaurs that had dominated during the Mesozoic.<ref>{{Cite journal |last1=Shupinski |first1=Alex B. |last2=Wagner |first2=Peter J. |last3=Smith |first3=Felisa A. |last4=Lyons |first4=S. Kathleen |date=3 July 2024 |title=Unique functional diversity during early Cenozoic mammal radiation of North America |journal=[[Proceedings of the Royal Society B: Biological Sciences]] |language=en |volume=291 |issue=2026 |doi=10.1098/rspb.2024.0778 |issn=1471-2954 |pmc=11286128 |pmid=38955231 |pmc-embargo-date=July 3, 2025 }}</ref> Birds also diversified rapidly; some flightless birds grew larger than humans. These species are sometimes referred to as "[[terror bird]]s", and were formidable predators. Mammals came to occupy almost every available [[ecological niche|niche]] (both marine and [[terrestrial animal|terrestrial]]), and some also grew very large, attaining sizes not seen in most of today's terrestrial mammals. The ranges of many Cenozoic bird clades were governed by latitude and temperature and have contracted over the course of this era as the world cooled.<ref>{{cite journal |last1=Saupe |first1=Erin E. |last2=Farnsworth |first2=Alexander |last3=Lunt |first3=Daniel J. |last4=Sagoo |first4=Navjit |last5=Pham |first5=Karen V. |last6=Field |first6=Daniel J. |date=10 June 2019 |title=Climatic shifts drove major contractions in avian latitudinal distributions throughout the Cenozoic |journal= Proceedings of the National Academy of Sciences|volume=116 |issue=26 |pages=12895–12900 |doi=10.1073/pnas.1903866116 |pmid=31182570 |pmc=6601418 |doi-access=free |bibcode=2019PNAS..11612895S }}</ref>

During the Cenozoic, [[Mammal evolution#Expansion of ecological niches in the Mesozoic|mammals proliferated]] from a few small, simple, generalised forms into a diverse collection of [[Terrestrial animal|terrestrial]], [[Marine mammal|marine]], and [[bat|flying]] animals, giving this period its other name, the Age of Mammals. The Cenozoic is just as much the age of [[savanna]]s, the age of co-dependent [[flowering plant]]s and [[insect]]s, and the age of birds.<ref>{{Cite web|url=https://ucmp.berkeley.edu/cenozoic/cenozoic.php|title=The Cenozoic Era|website=ucmp.berkeley.edu}}</ref> [[Grasses]] also played a very important role in this era, shaping the evolution of the birds and mammals that fed on them.  One group that diversified significantly in the Cenozoic as well were the [[snake]]s. Evolving in the Cenozoic, the variety of snakes increased tremendously, resulting in many [[colubrids]], following the evolution of their current primary prey source, the [[rodent]]s.

In the earlier part of the Cenozoic, the world was dominated by the [[Gastornithidae|gastornithid]] birds, terrestrial [[crocodylian]]s like ''[[Pristichampsus]]'', large sharks such as [[Otodus]], and a handful of primitive large mammal groups like [[uintathere]]s, [[Mesonychia|mesonychians]], and [[pantodont]]s. But as the forests began to recede and the climate began to cool, other mammals took over.

The Cenozoic is full of mammals both strange and familiar, including [[chalicothere]]s, [[creodont]]s, [[whale]]s, [[primate]]s, [[entelodont]]s, [[sabre-toothed cat]]s, [[mastodon]]s and [[mammoth]]s, [[three-toed horse]]s, giant [[rhinoceros]] like ''[[Paraceratherium]]'', the rhinoceros-like [[brontothere]]s, various bizarre groups of mammals from South America, such as the vaguely elephant-like [[pyrotheria|pyrothere]]s and the dog-like marsupial relatives called [[borhyaenidae|borhyaenids]] and the [[monotreme]]s and marsupials of Australia. Mammal evolution in the Cenozoic was predominantly shaped by climatic and geological processes.<ref>{{Cite journal |last1=Feijó |first1=Anderson |last2=Ge |first2=Deyan |last3=Wen |first3=Zhixin |last4=Cheng |first4=Jilong |last5=Xia |first5=Lin |last6=Patterson |first6=Bruce D. |last7=Yang |first7=Qisen |date=6 December 2022 |title=Mammalian diversification bursts and biotic turnovers are synchronous with Cenozoic geoclimatic events in Asia |journal=[[Proceedings of the National Academy of Sciences of the United States of America]] |language=en |volume=119 |issue=49 |pages=e2207845119 |doi=10.1073/pnas.2207845119 |doi-access=free |issn=0027-8424 |pmc=9894185 |pmid=36442115 |bibcode=2022PNAS..11907845F }}</ref><ref>{{Cite journal |last1=Juhn |first1=Mark S. |last2=Balisi |first2=Mairin A. |last3=Doughty |first3=Evan M. |last4=Friscia |first4=Anthony R. |last5=Howenstine |first5=Aidan O. |last6=Jacquemetton |first6=Christiane |last7=Marcot |first7=Jonathan |last8=Nugen |first8=Sarah |last9=Van Valkenburgh |first9=Blaire |date=30 September 2024 |title=Cenozoic climate change and the evolution of North American mammalian predator ecomorphology |url=https://www.cambridge.org/core/journals/paleobiology/article/cenozoic-climate-change-and-the-evolution-of-north-american-mammalian-predator-ecomorphology/CDF3786B3FA8A1DB57FF6CED340F33F3 |journal=[[Paleobiology (journal)|Paleobiology]] |volume=50 |issue=3 |language=en |pages=452–461 |doi=10.1017/pab.2024.27 |bibcode=2024Pbio...50..452J |issn=0094-8373 |access-date=8 November 2024 |via=Cambridge Core}}</ref>

Cenozoic [[Calcareous nannofossils|calcareous nannoplankton]] experienced rapid rates of speciation and reduced species longevity, while suffering prolonged declines in diversity during the Eocene and Neogene. [[Diatom|Diatoms]], in contrast, experienced major diversification over the Eocene, especially at high latitudes, as the world's oceans cooled.<ref>{{Cite journal |last=Bown |first=Paul R. |date=1 October 2005 |title=Calcareous nannoplankton evolution: a tale of two oceans |url=https://pubs.geoscienceworld.org/micropress/micropal/article-abstract/51/4/299/139808/Calcareous-nannoplankton-evolution-a-tale-of-two |journal=Micropaleontology |language=en |volume=51 |issue=4 |pages=299–308 |doi=10.2113/gsmicropal.51.4.299 |bibcode=2005MiPal..51..299B |issn=0026-2803 |access-date=8 January 2024 |via=GeoScienceWorld}}</ref> Diatom diversification was particularly concentrated at the Eocene-Oligocene boundary. A second major pulse of diatom diversification occurred over the course of the Middle and Late Miocene.<ref>{{Cite journal |last1=Falkowski |first1=Paul G. |last2=Katz |first2=Miriam E. |last3=Knoll |first3=Andrew H. |last4=Quigg |first4=Antonietta |last5=Raven |first5=John A. |last6=Schofield |first6=Oscar |last7=Taylor |first7=F. J. R. |date=16 July 2004 |title=The Evolution of Modern Eukaryotic Phytoplankton |url=https://www.science.org/doi/10.1126/science.1095964 |journal=[[Science (journal)|Science]] |language=en |volume=305 |issue=5682 |pages=354–360 |doi=10.1126/science.1095964 |pmid=15256663 |bibcode=2004Sci...305..354F |issn=0036-8075 |access-date=8 March 2024}}</ref>