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.

The area contains fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age.

The 100 km2 ( 39 sq mi ) area contains fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age.

* ( Note: this book contains very useful, information dense chapters on primate evolution in general, and human evolution in particular, including fossil history ).

* ( Note: this book contains very accessible descriptions of human and non-human primates, their evolution, and fossil history ).

The most recent part of the delta, which projects into the Adriatic between Chioggia and Comacchio, contains channels that actually connect to the Adriatic and on that account is called the active delta by the park authorities, as opposed to the fossil delta, which contains channels that no longer connect the Po to the Adriatic ( but once did ).

This huge aquifer, which underlies portions of eight states, contains primarily fossil water from the time of the last glaciation.

At around 400 million years old, the Rhynie chert contains the earliest fossil assemblage yielding plants preserved in sufficient detail to detect mycorrhizas-and they are indeed observed in the stems of Aglaophyton major.

The Riversleigh Fossil Fields Section of the park is a World Heritage Site and contains many fossil remains.

On the whole, the fossil record only contains mineralised exoskeletons, since these are by far the most durable.

For example, if a fossil assemblage contains more of one type of fossil than another, one can either infer that that organism was present in greater numbers, or that its remains were more resistant to decomposition.

The family Chinchillidae contains the chinchillas, viscachas, and their fossil relatives.

It contains one living and four fossil species of giant panda.

The family Castoridae contains the two living species of beaver and their fossil relatives.

Concretions are sometimes thought to be fossils, and occasionally one contains a fossil, but are generally not fossils themselves.

The Jurassic Coast contains a large range of important fossil zones.

The genus Urocyon ( from the Greek word for ' tailed dog ') is a genus that contains two ( or possibly three ) living Western Hemisphere foxes in the family Canidae, the Gray Fox ( Urocyon cinereoargenteus ) and the closely related Island Fox ( Urocyon littoralis ) which is a dwarf cousin of the Gray Fox ; as well as one fossil species, Urocyon progressus.

Most of her fossil collection is currently housed at the Academy of Natural Sciences of Philadelphia after purchase by Thomas Bellerby Wilson though small parts are in many British museums, in particular Leeds City Museum and possibly even in St. Petersburgh ; it contains many type specimens and some of the first fossils found ( and recognized though shortly after her death ) with the soft tissues preserved.

The second fossil zone, the 18 inch layer, is an unlaminated layer about thick that also contains abundant detailed fossils, but is harder to work because it is not composed of fissile laminae.

This site currently occupies ; it contains a complex of limestone caves, including the Sterkfontein Caves, where the 2. 3-million year-old fossil Australopithecus africanus ( nicknamed " Mrs. Ples ") was found in 1947 by Dr. Robert Broom and John T. Robinson.

The centre contains two levels, including a laser theatre, observatory, dinosaur and fossil exhibit, electronics exhibit and other attractions such as a setup demonstrating solar power with a model railroad and a forest logging simulation game.

The herbarium contains approximately 1. 5 million specimens of vascular plants, fungi, lichens, algae, and fossil plants.

The herbarium contains many specimens contributed by notable collectors, a diversity of fossil diatoms, and diatoms collected as part of numerous freshwater environmental surveys in the United States.