| Physogaleus | |
|---|---|
 | |
| Tooth of Physogaleus contortus from the Temblor Formation | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Order: | Carcharhiniformes |
| Genus: | † Physogaleus Cappetta, 1980 |
| Type species | |
| †Physogaleus secundus (Winkler, 1876) | |
| Species | |
| |
Physogaleus is an extinct genus of small requiem shark [4] that lived from the Late Paleocene [3] to Miocene epochs. [5] [6]
Physogaleus is only known from fossil teeth and isolated vertebra. The teeth similar to those of the modern Tiger shark, but are smaller, with a more central cusp that projects farther from the base of the tooth. The species of Physogaleus were originally described as belonging to the same genus as the modern Tiger shark, Galeocerdo . Recognition of numerous differences in dental anatomy of each these species compared other species of Galeocerdo lead researchers to erect the genus Physogaleus to include taxa that were more morphologically similar to one another than they were to Galeocerdo. [7]
Physogaleus teeth reach a maximum size that is smaller than that of true tiger sharks, and they lack the heavy serrations typical of Galeocerdo. They are also are more slender and the central cusp can be somewhat twisted toward the crown. This indicates individuals of Physogaleus probably had a diet of bony fish, similar to the living sand-tiger shark. [6]
The tiger shark is a species of ground shark, and the only extant member of the genus Galeocerdo and family Galeocerdonidae. It is a large macropredator, with females capable of attaining a length of over 5 m. Populations are found in many tropical and temperate waters, especially around central Pacific islands. Its name derives from the dark stripes down its body, which resemble a tiger's pattern, but fade as the shark matures.
Requiem sharks are sharks of the family Carcharhinidae in the order Carcharhiniformes. They are migratory, live-bearing sharks of warm seas and include such species as the bull shark, lemon shark, blacktip shark, and whitetip reef shark.
Galeocerdo is a genus of ground shark. Only a single species, G. cuvier, the tiger shark, is extant. The earliest fossils date back to the early Eocene epoch, (Ypresian), around 56–47.8 Million years ago. While historically considered a member of the requiem shark family Carcharhinidae, it is currently considered to be the only member of the family Galeocerdonidae. While this genus was historically considered diverse, including 21 extinct species, morphometric analysis conducted in 2021 suggested that the diversity of the genus included only 5 extinct species much lower than previously assumed. The oldest fossils of the extant G. cuvier date to the middle Miocene.
Carcharodon is a genus of sharks within the family Lamnidae, colloquially called the "white sharks." The only extant member is the great white shark. The extant species was preceded by a number of fossil (extinct) species including C. hubbelli and C. hastalis. The first appearance of the genus may have been as early as the Early Miocene or Late Oligocene. Carcharocles megalodon is still argued by some paleontologists to be a close relative of Carcharodon carcharias - as well as being in the same genus. The megalodon's scientific name was originally "Carcharodon" megalodon, but more recently, the giant shark has been assigned by most scientists to either the genus Carcharocles or Otodus.
Otodus megalodon, commonly known as megalodon, is an extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Early Pliocene epochs. O. megalodon was formerly thought to be a member of the family Lamnidae and a close relative of the great white shark, but has been reclassified into the extinct family Otodontidae, which diverged from the great white shark during the Early Cretaceous.
Otodus is an extinct, cosmopolitan genus of mackerel shark which lived from the Paleocene to the Pliocene epoch. The name Otodus comes from Ancient Greek ὠτ- and ὀδούς – thus, "ear-shaped tooth".
The rasptooth dogfish is a dogfish, found on the Kyushu–Palau Ridge in the northwest Pacific Ocean at depths of 360 m. Its maximum length is unknown. This species was originally described as Centroscyllium sheikoi, and subsequently allocated to the newly named genus Miroscyllium based on anatomical features not shared with other Centroscyllium. More recent molecular data suggest this species belongs to the genus Etmopterus, but as of June 2014 Miroscyllium sheikoi remains the valid name recognized by FishBase, the Catalog of Fishes World Register of Marine Species, and the IUCN
Otodus angustidens is an extinct species of prehistoric megatoothed sharks in the genus Otodus, which lived during the Late Eocene and Miocene epochs about 34 to 21 million years ago. The largest individuals were about 11–12 metres (36–39 ft) long. This shark is related to another extinct megatoothed shark, the famous Otodus megalodon.
Thalassocnus is an extinct genus of semiaquatic ground sloths from the Miocene and Pliocene of the Pacific South American coast. It is monotypic within the subfamily Thalassocninae. The five species—T. antiquus, T. natans, T. littoralis, T. carolomartini, and T. yuacensis—represent a chronospecies, a population gradually adapting to marine life in one direct lineage. They are the only known aquatic sloths, but they may have also been adapted to a terrestrial lifestyle. They have been found in the Pisco Formation of Peru, the Tafna Formation of Argentina, and the Bahía Inglesa, Coquimbo, and Horcón formations of Chile. Thalassocninae has been placed in both the families Megatheriidae and Nothrotheriidae.
Zygophyseter varolai is an extinct sperm whale that lived during the Tortonian age of the Late Miocene 11.2 to 7.6 million years ago. It is known from a single specimen from the Pietra Leccese Formation in Italy. It was a member of a stem group of fossil macroraptorial sperm whales also including Brygmophyseter, Acrophyseter, and Livyatan. It probably grew to be around 6.5 to 7 meters in length and shared some characteristics with other raptorials, such as large teeth with tooth enamel that were functional in both the upper and lower jaws which the modern sperm whale lacks. It also had a beak, the ability to echolocate prey, and could have probably swum faster than the modern-day sperm whale which can reach 4 kilometers per hour (2.5 mph). These were probably used in the capture of large prey, such as large fish, seals, and whales. In fact, its common name, the killer sperm whale, refers to its feeding habits that would have had a resemblance to the modern-day killer whale.
Lufengpithecus is an extinct genus of ape, known from the Late Miocene of East Asia. It is known from thousands of dental remains and a few skulls and probably weighed about 50 kg (110 lb). It contains three species: L. lufengensis, L. hudienensis and L. keiyuanensis. Lufengpithecus lufengensis is from the Late Miocene found in China, named after the Lufeng site and dated around 6.2 Ma. Lufengpithecus is either thought to be the sister group to Ponginae, or the sister to the clade containing Ponginae and Homininae.
Brygmophyseter, known as the biting sperm whale, is an extinct genus of toothed whale in the sperm whale family with one species, B. shigensis. When it was first described in 1994, the species was placed in the genus Scaldicetus based on tooth morphology, but this was later revised in 1995. In 2006, it was classified into the genus Naganocetus, which is considered to be a junior synonym. The only known specimen, a nearly complete skeleton, was dated to be around 16–15 million years old. Brygmophyseter is thought to have been 6.5–7 meters (21–23 ft) long, and it probably had 11 or 12 teeth in the upper and lower jaws. Brygmophyseter is part of a group of macroraptorial sperm whales which tended to be apex predators using their large teeth to catch struggling prey such as whales. It had a spermaceti organ which was probably used for biosonar like in the modern sperm whale. The whale has made an appearance on The History Channel's TV series Jurassic Fight Club.
Odontaspis and Greek: ἀσπίς aspís 'shield') is a genus of sand shark with two extant species.
Livyatan is an extinct genus of macroraptorial sperm whale containing one known species: L. melvillei. The genus name was inspired by the biblical sea monster Leviathan, and the species name by Herman Melville, the author of the famous novel Moby-Dick about a white bull sperm whale. Herman Melville often referred to whales as "Leviathans" in his book. It is mainly known from the Pisco Formation of Peru during the Tortonian stage of the Miocene epoch, about 9.9–8.9 million years ago (mya); however, finds of isolated teeth from other locations such as Chile, Argentina, the United States (California), South Africa and Australia imply that either it or a close relative survived into the Pliocene, around 5 mya, and may have had a global presence. It was a member of a group of macroraptorial sperm whales and was probably an apex predator, preying on whales, seals and so forth. Characteristically of raptorial sperm whales, Livyatan had functional, enamel-coated teeth on the upper and lower jaws, as well as several features suitable for hunting large prey.
Scaldicetus is an extinct genus of highly predatory macroraptorial sperm whale. Although widely used for a number of extinct physeterids with primitive dental morphology consisting of enameled teeth, Scaldicetus as generally recognized appears to be a wastebasket taxon filled with more-or-less unrelated primitive sperm whales.
Cosmopolitodus is an extinct genus of mackerel shark that lived between thirty and one million years ago during the late Oligocene to the Early Pleistocene epochs. Its type species is Cosmopolitodus hastalis, the broad-tooth mako. In 2021, Isurus planus was reassigned to the genus, and thus became the second species C. planus. However, some researchers still consider both species of Cosmopolitodus as species of Carcharodon.
Megalolamna is an extinct genus of large mackerel shark that lived from the Late Oligocene to the Middle Miocene. Fossils belonging to this genus are known from the Americas, Europe and Japan, and have been documented in scientific literature since the late 19th century. However, it was in 2016 that the fossils were described as belonging to the same distinct taxon called Megalolamna paradoxodon. However, a 2024 study reveals that the taxon was already described indirectly in 1879 under the name Otodus serotinus, the only known species of this genus then being renamed as Megalolamna serotinus. It is part of the Otodontidae, a family known to include the megalodon, of which this latter was also a contemporary. Although having a maximum length estimated at 5.1 m (17 ft), a measurement similar to that of the current great white shark, Megalolamna would have only fed on medium-sized prey. The front teeth of Megalolamna would have had the function of seizing the prey, before cutting it using the lateral teeth located at the corner of the mouth. Fossils proves that the genus had a cosmopolitan distribution and show that it inhabited mainly in shallow environments from tropical to mid-latitude areas.
Galeocerdo alabamensis is an extinct relative of the modern tiger shark. Nomenclature of this shark has been debated, and recent literature identified it more closely with the Physogaleus genus of prehistoric shark, rather than Galeocerdo. The classification of Physogaleus is known as tiger-like sharks while Galeocerdo refers to tiger sharks. In 2003, P. alabamensis was classified as Galeocerdo. However, in 2019, they were proclaimed to be more morphologically similar to the genus Physogaleus. This definition was based primarily on tooth shape, as the majority of information on P. alabamensis is a result of studying tooth fossils. Distinctions between Physogaleus and Galeocerdo are difficult with extinct sharks from the Oilgocene/Miocene as there is little paleobiological information allowing for hard conclusions.
Megachasma applegatei is an extinct species of megamouth shark from the Oligocene to early Miocene of the Western United States. The type fossil was discovered in the San Joaquin Valley in 1973, but only described in 2014, when the species was named after its discoverer, Shelton Applegate.
Danuvius guggenmosi is an extinct species of great ape that lived 11.6 million years ago during the Middle–Late Miocene in southern Germany. It is the sole member of the genus Danuvius. The area at this time was probably a woodland with a seasonal climate. A male specimen was estimated to have weighed about 31 kg (68 lb), and two females 17 and 19 kg. Both genus and species were described in November 2019.
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