This list of the Cenozoic life of Colorado contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Colorado and are between 66 million and 10,000 years of age.

A

Abies

†Abies longirostris

†Absarokius

†Absarokius abbotti – or unidentified comparable form

†Absarokius metoecus

†Absyrtus

†Absyrtus decrepitus – type locality for species

†Acaenitus

†Acaenitus defunctus – type locality for species

†Acalles

†Acalles exhumatus – type locality for species

†Acallomyia

†Acallomyia probolaea – type locality for species

†Acalyptus

†Acalyptus obtusus – type locality for species

†Acanthomyites – type locality for genus

†Acanthomyites aldrichi – type locality for species

†Acarictis – or unidentified comparable form

†Acarictis ryani

Acer

†Acer florissanti

†Acer fragile

†Acer macginitiei

†Acer oregonianum

†Achrestocoris – type locality for genus

†Achrestocoris cinerarius – type locality for species

†Acilius

†Acilius florissantensis – type locality for species

†Aciprion – type locality for genus

†Aciprion formosum – type locality for species

†Aciprion majus – type locality for species

†Acnemia

†Acnemia cyclosoma – type locality for species

†Acocephalus

†Acocephalus callosus – type locality for species

Acris

†Acritoparamys

†Acritoparamys atwateri

†Acritoparamys pattersoni

Acrostichum

†Acrostichum hesperium

†Acylophorus

†Acylophorus immotus – type locality for species

†Adalia

†Adalia subversa – type locality for species

†Adelocera

†Adelocera perantiqua – type locality for species

†Adelopsyche – type locality for genus

†Adelopsyche frustrans – type locality for species

†Adjidaumo

†Adjidaumo minimus

†Adjidaumo minutus

†Adocus

Aegialia

†Aegialia opaca

†Aelurodon

†Aelurodon asthenostylus

†Aepycamelus

†Aepycamelus giraffinus

Aeshna

†Aeshna larvata – type locality for species

†Aeshna solida – type locality for species

Agabus

†Agabus charon – type locality for species

†Agabus florissantensis – type locality for species

†Agabus infuscatus

†Agabus rathbuni – type locality for species

†Agallia

†Agallia abstructa – type locality for species

†Agallia flaccida – type locality for species

†Agallia instabilis – type locality for species

†Agallia lewisii – type locality for species

†Agathemera

†Agathemera reclusa – type locality for species

Agelaius

†Agelaius phoenicieus

†Agenia

†Agenia cockerellae – type locality for species

†Agenia saxigena – type locality for species

†Agnotocastor

†Agnotocastor coloradensis – type locality for species

Agoliinus

†Agoliinus plutonicus

Agrilus

†Agrilus liragus

†Agrilus praepolitus – type locality for species

†Agrion

†Agrion exsularis – type locality for species

†Agrion mascescens – type locality for species

†Agrion telluris – type locality for species

Agriotes

†Agriotes apicalis

†Agriotes comminutus – type locality for species

†Agriotes nearcticus – type locality for species

†Agromyza

†Agromyza praecursor – type locality for species

†Agulla

†Agulla protomaculata – type locality for species

†Agyrtes

†Agyrtes primoticus – type locality for species

†Ailanthus

†Ailanthus americana

†Ailanthus lesquereuxi

†Aleocharopsis

†Aleocharopsis caseyi – type locality for species

†Aleocharopsis secunda – type locality for species

†Alepidophora – type locality for genus

†Alepidophora cockerelli – type locality for species

†Alepidophora minor – type locality for species

†Alepidophora pealei – type locality for species

†Aletodon

†Aletodon gunnelli – or unidentified comparable form

Aleurites

†Aleurites glandulosa

†Alforjas – tentative report

†Alismaphyllites

†Alismaphyllites grandifolius

†Allantodiopsis

†Allantodiopsis erosa

†Allognathosuchus

†Allognathosuchus polyodon

†Allophaiomys

†Allophaiomys pliocaenicus

†Allophylus

†Allophylus flexifolia

List of the Cenozoic life of Colorado