According to the fossil record, Lissamphibia, which includes all modern amphibians and is the only surviving lineage, may have branched off from the extinct groups Temnospondyli and Lepospondyli at some period between the Late Carboniferous and the Early Triassic.

There are large gaps in the fossil record but the discovery of a proto-frog from the Early Permian in Texas in 2008 provided a missing link with many of the characteristics of modern frogs.

They are present in the lower Cambrian fossil record along with trilobites from the Redlichiida, Corynexochida, and Ptychopariida orders.

In contrast, their wide geographic dispersion in the fossil record is uncharacteristic of benthic animals, suggesting a pelagic existence.

However, as the preservation of behaviour in the fossil record is exceedingly rare, these ideas cannot readily be tested.

The fossil record of branchiopods extends back at least into the Upper Cambrian and possibly further.

The fossil record indicates that birds emerged within theropod dinosaurs during the Jurassic period, around 160 million years ( Ma ) ago.

Mineralized skeletons of bryozoans first appear in rocks from latest Cambrian period, about, making it the last major phylum to appear in the fossil record.

( The pre-Cambrian fossil record of animals is sparse and ambiguous.

Furthermore, great apes are not found in the fossil record in the Americas, and no Bigfoot remains have ever been found.

Paleobotanists study ancient plants in the fossil record.

Because the fossil record of chordates is poor, only molecular phylogenetics offers a reasonable prospect of dating their emergence.

Some fern orders such as Gleicheniales appeared as early in the fossil record as the Cretaceous, and achieved an early broad distribution.

The K – T boundary represents one of the most dramatic turnovers in the fossil record for various calcareous nanoplankton that formed the calcium deposits that gave the Cretaceous its name.

The turnover in this group is clearly marked at the species level .< ref > Statistical analysis of marine losses at this time suggests that the decrease in diversity was caused more by a sharp increase in extinctions than by a decrease in speciation .< ref > The K – T boundary record of dinoflagellates is not as well-understood, mainly because only microbial cysts provide a fossil record, and not all dinoflagellate species have cyst-forming stages, thereby likely causing diversity to be underestimated.

Radiolaria have left a geological record since at least the Ordovician times, and their mineral fossil skeletons can be tracked across the K – T boundary.

There is variability in the fossil record as to the extinction rate of marine invertebrates across the K – T boundary.

However, the fossil record for frog families and genera is uneven.

The dinosaur fossil record has been interpreted to show both a decline in diversity and no decline in diversity during the last few million years of the Cretaceous, and it may be that the quality of the dinosaur fossil record is simply not good enough to permit researchers to distinguish between the options.

Whether the extinction occurred gradually or very suddenly is debatable, as both views have support in the fossil record.

For example, periods of high oxygen concentrations determined from ice core samples have been associated with fauna of a larger scale in the fossil record, while periods of low oxygen concentrations have been associated with fauna of a smaller scale in the fossil record.

A 40-year study of African, Asian, and South American tropical forests by the University of Leeds, shows tropical forests absorb about 18 % of all carbon dioxide added by fossil fuels.

The fossil record shows Homo sapiens living in southern and eastern Africa at least 100, 000 and possibly 150, 000 years ago.

As the fossil record for the Cryptobranchidae shows an Asian origin for the family, the story of how these salamanders made it to the eastern U. S. has been a point of scientific interest.

DNA evidence shows the lion, tiger, leopard, jaguar, snow leopard, and clouded leopard share a common ancestor, and that this group is between six and ten million years old ; the fossil record points to the emergence of Panthera just two to 3. 8 million years ago.

Current fossil and DNA evidence shows that all existing species can trace a continual ancestry back to the first primitive life forms.

The only solid evidence for social behavior among dromaeosaurids comes from a Chinese trackway of fossil footprints, which shows six individuals of a large species moving as a group, though no evidence of cooperative hunting was found.

Further, because the fossil bone shows no sign of healing near the bite wounds, the injury probably killed it.

The current paucity of auks in the Atlantic ( 6 species ), compared to the Pacific ( 19-20 species ) is considered to be because of extinctions to the Atlantic auks ; the fossil record shows there were many more species in the Atlantic during the Pliocene.

The fossil record shows sirenians appearing in the Eocene, where they most likely lived in the Tethys Ocean.

Proponents of the AAH suggest that bipedalism is disadvantageous when comparing humans to medium sized, terrestrial quadrupeds, but the fossil record shows that the evolution of humans from ape ancestors didn't include a period of quadrupedal locomotion.

A single fossil of hagfish shows that there has been little evolutionary change in the last 300 million years.

As a result, the fossil record for a region shows abrupt changes in species.

He goes on to argue that the absence of cuticle is characteristic of the Chaetognaths ; whilst teeth would be expected, a similar fossil, Wiwaxia, only shows such structures in 10 % of the expected instances, and Anamolocarids are often found detached from their mouthparts, so the absence may be taphonomic rather than genuine.

The Eomaia fossil shows clear traces of hair.

The New Zealand Rockwren is specialised for the alpine environment, in areas of low scrub and scree from 900 m up to 2, 400 m. Contrary to its other common name ( the South Island Wren ) fossil evidence shows it was more widespread in the past and lived on North Island.

Since Placentalia therefore includes all living eutherians, the nonplacental eutherians are necessarily extinct ; the picture to the right shows a fossil of one such animal, Eomaia.

* 1796 — Cuvier presents a paper on living and fossil elephants that shows that mammoths were a different species from any living elephant.

* 1800 — Cuvier writes that a drawing of a fossil found in Bavaria shows a flying reptile ; in 1809 he names it Pterodactyl.

* 1982 — Jack Sepkoski and David M. Raup publish a statistical analysis of the fossil record of marine invertebrates that shows a pattern ( possibly cyclical ) of repeated mass extinctions.

The fact that Leefructus shows a well developed structure similar to modern ranunculids suggests that this group of eudicots may have developed erlier than the age of the fossil.

While the family is now restricted to sub-Saharan Africa, fossil evidence shows that the family once had a larger distribution.

The fossil record shows aspects of the meandering evolutionary path from early aquatic vertebrates to mammals, with a host of transitional fossils, though there are still large blank areas.

It shows shows the progression of evolution in fossil fish, and amphibians and reptiles through comparative anatomy, including a list of all the ( then ) known fossil vertebrate genera.