answersLogoWhite

0

40 million years ago
They started appearing in the Cenozoic period.

What else can I help you with?

Continue Learning about Natural Sciences

What did small mammals appear in the fossil records?

Small mammals first appeared in the fossil record during the late Triassic period, around 200 million years ago. These early mammals were generally small, nocturnal creatures that evolved from therapsid ancestors. Fossils from this time indicate that they were primarily insectivorous, adapted to a life in the shadows of larger dinosaurs. Over millions of years, small mammals diversified significantly, eventually leading to the wide variety of species we see today.


When did mammals first appear on earth by paleontologists?

Mammals first appear in the fossil record of the Mesozoic Era.


When did the first primitive mammals appear in the fossil record in what period?

The first primitive mammals appeared in the fossil record during the Late Triassic period, approximately 225 million years ago. These early mammals were small, shrew-like creatures that lived alongside dinosaurs. The emergence of mammals marked a significant evolutionary development, leading to the diverse range of species we see today.


Why is it impossible for a cat fossil to be found in the same sedimentary rock layer as a dinosaur fossil?

Because the layer dinosaur fossils are located are from time period and the fact there were no mammals (cat like) on that time, makes it impossible for cats to be found on that layer. Actually the first mammals appear in the fossil record about the same time as the first dinosaurs, but until at the time the dinosaurs died out (65 million years ago) no mammal was quite as large as the modern cat (most were the size of rats or smaller). The first cats (and "dogs") did not appear until about 50 million years ago.


Why it is hard to find fossil records in layers of rock.?

because it hiding in the records of the rock

Related Questions

When do small mammals appear in fossil records?

During the KT extinction event the majority of life on earth became extinct. Small mammals, however, were able to survive this mass extinction.


Are fossils records complete or incomplete?

Fossil records are not complete. By some estimates, less than 1% of organisms that have lived appear in the fossil record.


When did dolphins appear on earth?

Fossil records suggest that dolphins evolved around 10-15 million years ago during the Miocene epoch. They are believed to have evolved from land-dwelling mammals that returned to the sea.


What did small mammals appear in the fossil records?

Small mammals first appeared in the fossil record during the late Triassic period, around 200 million years ago. These early mammals were generally small, nocturnal creatures that evolved from therapsid ancestors. Fossils from this time indicate that they were primarily insectivorous, adapted to a life in the shadows of larger dinosaurs. Over millions of years, small mammals diversified significantly, eventually leading to the wide variety of species we see today.


When did modern humans appear on earth according to fossil records?

According to the fossil records, the modern humans did appear on earth more than 130,000 years ago.


When did mammals first appear on earth by paleontologists?

Mammals first appear in the fossil record of the Mesozoic Era.


In general the first mammals of any group to appear in the fossil record?

resembled dogs and cats


When did the first primitive mammals appear in the fossil record in what period?

The first primitive mammals appeared in the fossil record during the Late Triassic period, approximately 225 million years ago. These early mammals were small, shrew-like creatures that lived alongside dinosaurs. The emergence of mammals marked a significant evolutionary development, leading to the diverse range of species we see today.


Did mammals appear in the fossil record after dinosaurs became extinct?

No, mammals lived alongside dinosaurs and their earliest known fossils of about 200 million years old are almost contemporary with the early dinosaur fossils.


What has the author Mietje Germonpre written?

Mietje Germonpre has written: 'The Belgian quaternary mammals' -- subject(s): Bibliography, Fossil Mammals, Mammals, Fossil, Paleontology


What has the author William Wise written?

William Wise has written: 'Nanette the hungry pelican' 'The world of giant mammals' -- subject(s): Fossil Mammals, Mammals, Fossil 'The cowboy surprise' 'The terrible trumpet'


What has the author Jin Meng written?

Jin Meng has written: 'The osteology of Rhombomylus (Mammalia, Glires)' -- subject(s): Fossil Mammals, Mammals, Fossil, Paleontology