A number of fossil cryptobranchids have been found but there are only three living species, the Chinese giant salamander ( Andrias davidianus ), the Japanese giant salamander ( Andrias japonicus ) and the hellbender ( Cryptobranchus alleganiensis ) from North America.

This fossil was originally described as a species of Australopithecus, but White and his colleagues later published a note in the same journal renaming the fossil under a new genus, Ardipithecus.

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.

Others have interpreted the fossil bearing rocks along Red Deer River in Alberta, Canada, as supporting a gradual extinction of non-avian dinosaurs ; during the last 10 million years of the Cretaceous layers there, the number of dinosaur species seems to have decreased from about 45 to about 12.

In the 1980s Ethiopia emerged as the new hot spot of palaeoanthropology as " Lucy ", the most complete fossil member of the species Australopithecus afarensis, was found by Don Johanson in Hadar in the desertic Middle Awash region of northern Ethiopia.

By constructing a calibration curve of the ID of species ' pairs with known divergence times in the fossil record, the data could be used as a molecular clock to estimate the times of divergence of pairs with poorer or unknown fossil records.

The question of the relation between these early fossil species and the hominin lineage is still to be resolved.

The australopithecine species that are best represented in the fossil record is Australopithecus Afarensis with more than a hundred fossil individuals represented, found from Northern Ethiopia ( such as the famous " Lucy "), to Kenya, and South Africa.

The surviving tropical population of primates, which is seen most completely in the upper Eocene and lowermost Oligocene fossil beds of the Faiyum depression southwest of Cairo, gave rise to all living species — lemurs of Madagascar, lorises of Southeast Asia, galagos or " bush babies " of Africa, and the anthropoids: platyrrhine or New World monkeys, catarrhines or Old World monkeys, and the great apes, including humans.

* In February 2006 a fossil, the Gawis cranium, was found which might possibly be a species intermediate between H. erectus and H. sapiens or one of many evolutionary dead ends.

A Homo fossil was found near some Oldowan tools, and its age was noted at 2. 3 million years old, suggesting that maybe the Homo species did indeed create and use these tools.

Paleontologist Donald Prothero noted that this is illustrated by the fact that the number of species known through the fossil record is less than 5 % of the number of known living species, suggesting that the number of species known through fossils must be far less than 1 % of all the species that have ever lived.

They work on the premise that, although different sediments may look different depending on the conditions under which they were laid down, they may include the remains of the same species of fossil.

Paleontologists examine the fossil record in order to understand the process of evolution and the way particular species have evolved.

Prior to this discovery, biologists had been largely unable to establish a family tree of cats from the fossil record because the fossils of different cat species all look very much alike, differing primarily in size.

The fossil record ( especially the sister species Pinguinus alfrednewtoni ) and molecular evidence show that the three genera, while closely related, diverged soon after their common ancestor, a bird probably similar to a stout Xantus's Murrelet, had spread to the coasts of the Atlantic.

As fossil striped hyenas are absent from the Mediterranean region, it is likely that the species is a relatively late invader to Eurasia, having likely spread outside Africa only after the extinction of spotted hyenas in Asia at the end of the Ice Age.

The total number of fossil felids that are known to science is low compared to other carnivoran families such as dogs and bears.

Unlike most vertebrates, which walk on their toes with ankles held off the ground ( digitigrade ), fossil footprints show that pterosaurs stood with the entire foot in contact with the ground ( plantigrade ), in a manner similar to humans and bears.

From the Holocene to present, American black bears seem to have shrunk in size, but this has been disputed because of problems with dating these fossil specimens.

The fossil bears a distinct axial ledge consisting of two parallel bands extending from the head region to the posterior end of the body.

Active excavation site at La Brea Tar Pits, 2008Among the prehistoric species associated with the La Brea Tar Pits are mammoths, dire wolves, short-faced bears, ground sloths, and the state fossil of California, the saber-toothed cat, Smilodon fatalis.

Romer was the first to recognise the gap in the fossil record between the early land fauna of the Devonian and the later Carboniferous period, a gap that still bears the name Romer's gap.

An example of directional selection is fossil records that show that the size of the black bears in Europe decreased during interglacial periods of the ice ages, but increased during each glacial period.

Skania is a Cambrian fossil arthropod that may be related to the Ediacaran organism Parvancorina, and bears a strong, albeit superficial resemblance to the Vendiamorphans Vendia, Praecambridium and Onega.

An in-depth mitochondrial DNA population analysis study stated: “ According to the fossil record, the Red Panda diverged from its common ancestor with bears about 40 million years ago ( Mayr 1986 ).

The Darwin fish bears a stylized resemblance to Ichthyostega, which is a major example of a transitional fossil.

Genetic divergence of mangrove lineages from terrestrial relatives, in combination with fossil evidence, suggests mangrove diversity is limited by evolutionary transition into the stressful marine environment, and the number of mangrove lineages has increased steadily over the Tertiary with little global extinction.

Several waste gasification processes have been proposed, but few have yet been built and tested, and only a handful have been implemented as plants processing real waste, and most of the time in combination with fossil fuels.

Electric vehicles differ from fossil fuel-powered vehicles in that the electricity they consume can be generated from a wide range of sources, including fossil fuels, nuclear power, and renewable sources such as tidal power, solar power, and wind power or any combination of those.

The combination of solar water heating and using the back-up heat from a wood stove chimney to heat water can enable a hot water system to work all year round in cooler climates, without the supplemental heat requirement of a solar water heating system being met with fossil fuels or electricity.

" The behavior of the raptors and other animals featured in the novel was based on a combination of fossil evidence and observations of modern animals, such as chimpanzees and alligators.

The sand and silt often contain either volcanic glass, fossil plants, rhyolite pebbles, or some combination of them.

The fossil has been dated by a combination of palaeomagnetism and uranium-lead techniques to around 2. 05 million years.

Skeptics claim that many of the allegedly hominin-like features seen in the Ardipithecus material are found elsewhere among living and fossil primates, and that claims about its hominin status and locomotor habits are not adequately supported by the available evidence.

The earliest known example of a fossil skeleton with negroid features, perhaps 10, 000 years old, was found at Iii Ileru in western Nigeria and attests to the antiquity of habitation in the region.

Its skull is frog-like, being broad with large eye sockets, but the fossil has features diverging from modern frogs.

Cladistics, a modern form of systematics research, is based exclusively on demonstrable features of living and fossil animal groups ( taxa ) for reconstructing the genealogy of a species or group.

In particular, if Toumaï is a direct human ancestor, then its facial features bring the status of Australopithecus into doubt because its thickened brow ridges were reported to be similar to those of some later fossil hominids ( notably Homo erectus ), whereas this morphology differs from that observed in all australopithecines, most fossil hominids and extant humans.

Quillworts are considered by some to be the last remnant of the fossil tree Lepidodendron with which they share some unusual features including the development of both wood and bark, a modified shoot system acting as roots, bipolar growth, and an upright stance.

Opened in 1981, it is home to an amphitheater, nature trails, and a stocked fishing pond, as well as the Interpretive Center, a small museum which features ice age fossil and local geology exhibits.

Also reported was a Devonian Chinese fossil fish, Styloichthys changae, that has features linking the lungfish to tetrapods ( four-legged vertebrates ).

Despite the existence of a fossil record, full classification and phylogeny of the sturgeon species has been difficult to determine, in part due to the high individual and ontogenic variation, including geographical clines in certain features, such as rostrum shape, number of scutes and body length.

Because these fossils lack features diagnostic for identification at even the highest level, they are assigned to fossil form taxa according to their shape and other gross morphological features.

These features seemed to make the tail into a stiff counterbalance, but a fossil of the very closely related Velociraptor mongoliensis ( IGM 100 / 986 ) has an articulated tail skeleton that is curved laterally in a long S – shape.

Exhibiting several " primitive " features, the frilled shark has often been termed a " living fossil ".

Another Oligocene fossil from Europe, Parvigrus pohli ( family Parvigruidae ), has been described as a mosaic of the features shared by the limpkins and the cranes.

The face ( fossil KNM-ER 62000 ) was of a juvenile, but had features in common with KNM-ER 1470, suggesting that the latter skull's uniqueness is due to being a separate species, rather than a large male H. habilis.

A more recent classification divided the subfamilies and genera based on the consideration of features of ovulate cone anatomy among extant and fossil members of the family.

These features make Archaeopteryx a clear candidate for a transitional fossil between dinosaurs and birds, making it important in the study both of dinosaurs and of the origin of birds.

Note that just because a living fossil is a surviving representative of an archaic lineage does not necessarily require that it retains all of the " primitive " features ( plesiomorphies ) of the lineage it is descended from ; that is, they may possess one to many derived features ( autapomorphies ), that have evolved since the time of their lineage's divergence.

Note that, as mentioned above, the converse may hold for true living fossil taxa ; that is, they may possess a great many derived features ( autapomorphies ), and not be particularly " primitive " in appearance. The trapdoor spider has segmented plates on its back, making it the most ancient of all living spiders and the closest relative to the scorpions in the spider family.

In spite of many of them being poorly known, fossil remains show that they shared features such as enlarged heads and jaws, reduced pectoral elements, and robust leg elements.

" The many morphological features shared by the Herto crania and AMHS, to the exclusion of penecontemporanous Neanderthals, provide additional fossil data excluding Neanderthals from a significant contribution to the ancestry of modern humans.

Baronia brevicornis is considered to be a relict species, and shares features with a fossil taxon Praepapilio.