Extinct in the context of King Island emu

Oleaceae (/ˌoʊliˈeɪsi.iː, -ˌaɪ/), also known as the olive family or sometimes the lilac family, is a taxonomic family of flowering shrubs, trees, and a few lianas in the order Lamiales. It presently comprises 28 genera, one of which is recently extinct. The extant genera include Cartrema, which was resurrected in 2012. The number of species in the Oleaceae is variously estimated in a wide range around 700. The flowers are often numerous and highly odoriferous. The family has a subcosmopolitan distribution, ranging from the subarctic to the southernmost parts of Africa, Australia, and South America. Notable members include olive, ash, jasmine, and several popular ornamental plants including privet, forsythia, fringetrees, and lilac.

Life is matter that has biological processes, such as signaling and the ability to sustain itself. It is defined descriptively by the capacity for homeostasis, organisation, metabolism, growth, adaptation, response to stimuli, and reproduction. All life over time eventually reaches a state of death, and none is immortal. Many philosophical definitions of living systems have been proposed, such as self-organizing systems. Defining life is further complicated by viruses, which replicate only in host cells, and the possibility of extraterrestrial life, which is likely to be very different from terrestrial life. Life exists all over the Earth in air, water, and soil, with many ecosystems forming the biosphere. Some of these are harsh environments occupied only by extremophiles. The life in a particular ecosystem is called its biota.

Life has been studied since ancient times, with theories such as Empedocles's materialism asserting that it was composed of four eternal elements, and Aristotle's hylomorphism asserting that living things have souls and embody both form and matter. Life originated at least 3.5 billion years ago, resulting in a universal common ancestor. This evolved into all the species that exist now, by way of many extinct species, some of which have left traces as fossils. Attempts to classify living things, too, began with Aristotle. Modern classification began with Carl Linnaeus's system of binomial nomenclature in the 1740s.

Homo (from Latin homō 'human') is a genus of great ape (family Hominidae) that emerged from the early homininian genus Australopithecus, encompassing a single extant species, Homo sapiens (modern humans), along with a number of extinct species (e.g. Homo erectus and Homo neanderthalensis) classified as either ancestral or closely related to modern humans, collectively called archaic humans. Homo, together with the genus Paranthropus, is probably most closely related to the species Australopithecus africanus within Australopithecus. The closest living relatives of Homo are of the hominin genus Pan (chimpanzees and bonobos), with the ancestors of Pan and Homo estimated to have diverged around 5.7–11 million years ago during the Late Miocene.

The oldest member of the genus is Homo habilis, with fossil records of just over 2 million years ago. H. erectus appeared about 2 million years ago and spread throughout Africa (debatably as another species called Homo ergaster) and Eurasia in several migrations. The species was adaptive and successful, and persisted for more than a million years before gradually diverging into new species around 500,000 years ago.

Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (/ˈmɒləsks/). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The number of additional fossil species is estimated between 60,000 and 100,000, and the proportion of undescribed species is very high. Many taxa remain poorly studied.

Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat, as numerous groups are freshwater and even terrestrial species. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known extant invertebrate species. The gastropods (snails, slugs and abalone) are by far the most diverse class and account for 80% of the total classified molluscan species.

Homo antecessor (Latin for 'pioneer man') is an extinct species of archaic human recorded in the Spanish Sierra de Atapuerca, a productive archaeological site, from 1.2 to 0.8 million years ago during the Early Pleistocene. Populations of this species may have been present elsewhere in Western Europe, and were among the first to settle that region of the world, hence the name. The first fossils were found in the Gran Dolina cave in 1994, and the species was formally described in 1997 as the last common ancestor of modern humans and Neanderthals, supplanting the more conventional H. heidelbergensis in this position. H. antecessor has since been reinterpreted as an offshoot from the modern human line, although probably one branching off just before the modern human/Neanderthal split.

Despite being so ancient, the face is unexpectedly similar to that of modern humans rather than other archaic humans—namely in its overall flatness as well as the curving of the cheekbone as it merges into the upper jaw—although these elements are known only from a juvenile specimen. Brain volume could have been 1,000 cc (61 cu in) or more, but no intact braincase has been discovered. This is within the range of variation for modern humans. Stature estimates range from 162.3–186.8 cm (5 ft 4 in – 6 ft 2 in). H. antecessor may have been broad-chested and rather heavy, much like Neanderthals, although the limbs were proportionally long, a trait more frequent in tropical populations. The kneecaps are thin and have poorly developed tendon attachments. The feet indicate H. antecessor walked differently than modern humans.

In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two end populations in the series which are too distantly related to interbreed, though there is a potential gene flow between linked neighbouring populations. Such non-breeding, though genetically connected, end populations may co-exist in the same region (sympatry) thus closing a ring. The German term Rassenkreis, meaning "circle of races", is also used.

Ring species represent speciation and have been cited as evidence of evolution. They illustrate what happens over time as populations genetically diverge, specifically because they represent, in living populations, what normally happens over time between long-deceased ancestor populations and living populations, in which the intermediates have become extinct. The evolutionary biologist Richard Dawkins remarks that ring species "are only showing us in the spatial dimension something that must always happen in the time dimension".

In biology, a clade (//kleɪd//) (from Ancient Greek κλάδος (kládos) 'branch'), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy adopted by most biological fields.

The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups.

Archosauria (lit. 'ruling reptiles') or archosaurs (/ˈɑːrkəˌsɔːr/) is a clade of diapsid sauropsid tetrapods, with birds and crocodilians being the only known extant representatives. Although broadly classified as reptiles, which traditionally exclude birds, the cladistic sense of the term includes all living and extinct relatives of birds and crocodilians such as non-avian dinosaurs, pterosaurs, phytosaurs, aetosaurs and rauisuchians as well as many Mesozoic marine reptiles. Modern paleontologists define Archosauria as a crown group that includes the most recent common ancestor of living birds and crocodilians, and all of its descendants.

The base of Archosauria splits into two clades: Pseudosuchia, which includes crocodilians and their extinct relatives; and Avemetatarsalia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs). Older definitions of the group Archosauria rely on shared morphological characteristics, such as an antorbital fenestra in the skull, serrated teeth, and an upright stance. Some extinct reptiles, such as proterosuchids and euparkeriids, also possessed these features yet originated prior to the split between the crocodilian and bird lineages. The older morphological definition of Archosauria nowadays roughly corresponds to Archosauriformes, a group named to encompass crown-group archosaurs and their close relatives.

Pangolins, sometimes known as scaly anteaters, are mammals of the order Pholidota (/fɒlɪˈdoʊtə/). The one extant family, the Manidae, has three genera: Manis, Phataginus, and Smutsia. Manis comprises four species found in Asia, while Phataginus and Smutsia include two species each, all found in sub-Saharan Africa. These species range in size from 30 to 100 cm (12 to 39 in). Several extinct pangolin species are also known. In September 2023, nine species were reported.

Pangolins have large, protective keratin scales, similar in material to fingernails and toenails, covering their skin; they are the only known mammals with this feature. Depending on the species, they live in hollow trees or burrows. Pangolins are nocturnal, and their diet consists of mainly ants and termites, which they capture using their long tongues. They tend to be solitary animals, meeting only to mate and produce a litter of one to three offspring, which they raise for about two years. Pangolins superficially resemble armadillos, though the two are not closely related; they have undergone convergent evolution.

The Atlas Mountains are a mountain range in the Maghreb in North Africa. They separate the Sahara Desert from the Mediterranean Sea and the Atlantic Ocean; the mountain range stretches around 2,500 km (1,600 mi) through Morocco, Algeria and Tunisia. The mountains are associated with the Titan Atlas. The range's highest peak is Toubkal, in central Morocco, with an elevation of 4,167 metres (13,671 ft). The Atlas Mountains are primarily inhabited by Berber populations.

The terms for 'mountain' are Adrar and adras in some Berber languages, and these terms are believed to be cognates of the toponym Atlas. The mountains are home to a number of animals and plants which are mostly found within Africa but some of which can be found in Europe. Many of these species are endangered and a few are already extinct. The weather is generally cool but summers are sunny, and the average temperature there is 25 °C.

Osteichthyes (/ˌɒstiːˈɪkθiːz/ ost-ee-IK-theez; from Ancient Greek ὀστέον (ostéon) 'bone' and ἰχθύς (ikhthús) 'fish'), also known as osteichthyans or commonly referred to as the bony fish, is a diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes (cartilaginous fish) and the extinct placoderms and acanthodians, which have endoskeletons primarily composed of cartilage. The vast majority of extant fish are members of Osteichthyes, being an extremely diverse and abundant group consisting of 45 orders, over 435 families and 28,000 species.

The group is divided into two main clades, the ray-finned fish (Actinopterygii, which makes up the vast majority of extant fish) and the lobe-finned fish (Sarcopterygii, which gave rise to all land vertebrates, i.e. tetrapods). The oldest known fossils of bony fish are about 425 million years old from the late Silurian, which are also transitional fossils showing a tooth pattern that is in between the tooth rows of sharks and true bony fishes. Despite the name, these early basal bony fish had not yet evolved ossification and their skeletons were still mostly cartilaginous, and the main distinguishing feature that set them apart from other fish clades were the development of foregut pouches that eventually evolved into the swim bladders and lungs, respectively.

Onychocrinus is an extinct genus of feathered crinoids that lived during the Carboniferous period, approximately 353.8 to 318.1 million years ago. It belonged to the family Synerocrinidae.

Gryphaea, one of the genera known as devil's toenails, is a genus of extinct oysters, marine bivalve mollusks in the family Gryphaeidae.

These fossils range from the Triassic period to the middle Paleogene period, but are mostly restricted to the Triassic and Jurassic. They are particularly common in many parts of Britain.

Harpactocarcinus is an extinct genus of mud crabs.

Tiktaalik (/tɪkˈtɑːlɪk/; Inuktitut: ᑎᒃᑖᓕᒃ [tiktaːlik]) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the late Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals). Tiktaalik is estimated to have had a total length of 1.25–2.75 metres (4.1–9.0 ft) on the basis of various specimens.

Unearthed in Arctic Canada, Tiktaalik is a non-tetrapod member of Osteichthyes (bony fish), complete with scales and gills—but it has a triangular, flattened head and unusual, cleaver-shaped fins. Its fins have thin ray bones for paddling like most fish, but they also have sturdy interior bones that would have allowed Tiktaalik to prop itself up in shallow water and use its limbs for support as most four-legged animals do. Those fins and other mixed characteristics mark Tiktaalik as a crucial transition fossil, a link in evolution from swimming fish to four-legged vertebrates. This and similar animals might be the common ancestors of all vertebrate terrestrial fauna: amphibians, reptiles, birds and mammals.

The Cretaceous (IPA: /krɪˈteɪʃəs/ krih-TAY-shəss) is a geologic period that lasted from about 143.1 to 66 Ma (million years ago). It is the third and final period of the Mesozoic Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin creta, 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation Kreide.

The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles.