Echolocation, also called bio sonar, is a biological active sonar used by several animal groups, both in the air and underwater. Echolocating animals emit calls and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for navigation, foraging, and hunting prey.
Viridiplantae constitute a clade of eukaryotic organisms that comprises approximately 450,000–500,000 species that play important roles in both terrestrial and aquatic ecosystems. They include the green algae, which are primarily aquatic, and the land plants (embryophytes), which emerged from within them. Green algae traditionally excludes the land plants, rendering them a paraphyletic group. However it is accurate to think of land plants as a kind of alga. Since the realization that the embryophytes emerged from within the green algae, some authors are starting to include them. They have cells with cellulose in their cell walls, and primary chloroplasts derived from endosymbiosis with cyanobacteria that contain chlorophylls a and b and lack phycobilins. Corroborating this, a basal phagotroph archaeplastida group has been found in the Rhodelphydia.
Archaeoceti, or Zeuglodontes in older literature, is a paraphyletic group of primitive cetaceans that lived from the Early Eocene to the late Oligocene. Representing the earliest cetacean radiation, they include the initial amphibious stages in cetacean evolution, thus are the ancestors of both modern cetacean suborders, Mysticeti and Odontoceti. This initial diversification occurred in the shallow waters that separated India and Asia 53 to 45 mya, resulting in some 30 species adapted to a fully oceanic life. Echolocation and filter-feeding evolved during a second radiation 36 to 35 mya.
Caninae ,) is the only living subfamily within Canidae, alongside the extinct Borophaginae and Hesperocyoninae. They first appeared in North America, during the Oligocene around 35 million years ago, subsequently spreading to Asia and elsewhere in the Old World at the end of the Miocene, some 7 million to 8 million years ago.
Aetiocetus is a genus of extinct basal mysticete, or baleen whale that lived 33.9 to 23.03 million years ago, in the Oligocene in the North Pacific ocean, around Japan, Mexico, and Oregon, U.S. It was first described by Douglas Emlong in 1966 and currently contains known four species, A. cotylalveus, A. polydentatus, A. tomitai, and A. weltoni. These whales are remarkable for their retention of teeth and presence of nutrient foramina, indicating that they possessed baleen. Thus, Aetiocetus represents the transition from teeth to baleen in Oligocene mysticetes. Baleen is a highly derived character, or synapomorphy, of mysticetes, and is a keratinous structure that grows from the palate, or roof of the mouth, of the whale. The presence of baleen is inferred from the fossil record in the skull of Aetiocetus. Aetiocetus is known from both sides of the Pacific Ocean: it was first documented in Oregon, United States, but it is also known from Japan and Mexico. The genus is currently constrained to the Northern hemisphere and has little value in biostratigraphic studies of the Oligocene due to its limited occurrences across the Pacific.
Kentriodontidae is an extinct family of odontocete whales related to modern dolphins. The Kentriodontidae lived from the Oligocene to the Pliocene before going extinct.
The Ashley Formation is a geologic formation in South Carolina. It preserves fossils dating back to the Paleogene period.
The Chandler Bridge Formation is a geologic formation in South Carolina. It preserves fossils dating back to the Chattian of the Paleogene period, corresponding to the Arikareean in the NALMA classification. The formation overlies the Ashley Formation and is overlain by the Edisto Formation.
The Alsea Formation is a geologic formation in Oregon. It preserves fossils dating back to the Rupelian stage of the Oligocene period.
Aetiocetidae is an extinct family of toothed baleen whales known from the Oligocene and latest Eocene, so far only from rocks deposited in the North Pacific Ocean. The whales ranged in size from 3 to 8 metres long. Many of the described specimens were discovered from the Upper Oligocene of the Japanese Morawan Formation, the largest known one from the Morawan's Upper tuffaceous siltstone. Other formally described extinct toothed mysticetis from this time are smaller, from 3 to 4 metres in length. Mysticeti with true baleen are seen in fossils from the Upper Oligocene. The monophyly of the family is still uncertain, as are the evolutionary relationship between the early toothed baleen whales and the early and extant edentulous baleen whales. However, the cladistic analyses of Coronodon and Mystacodon seem to indicate that Aetiocetidae and Llanocetidae are more closely related to crown Mysticeti than to Mammalodontidae, Coronodon, and Mystacodon.
This paleomammalogy list records new fossil mammal taxa that were described during the year 2017, as well as notes other significant paleomammalogy discoveries and events which occurred during that year.
This paleomammalogy list records new fossil mammal taxa that were described during the year 2016, as well as notes other significant paleomammalogy discoveries and events which occurred during that year.
Coronodon is a genus of toothed (transitional) baleen whales from the Early Oligocene Ashley and Chandler Bridge formations of South Carolina. The genus contains three species: the type species C. havensteini, and additional species C. newtonorum and C. planifrons.
Xenorophus is a genus of primitive odontocete from late Oligocene (Chattian) marine deposits in South Carolina. It belongs to the Xenorophidae.
Echovenator is a genus of primitive odontocete from late Oligocene (Chattian) marine deposits in South Carolina. It belongs to the Xenorophidae.
Cotylocara is a genus of primitive odontocete from late Oligocene (Chattian) marine deposits of the Chandler Bridge Formation of South Carolina. It belongs to the Xenorophidae.
Albertocetus is an extinct genus of primitive odontocete cetacean from early Oligocene (Rupelian) marine deposits in North Carolina, and belonging to the family Xenorophidae.
Inermorostrum is a genus of primitive odontocete from early Oligocene (Rupelian) marine deposits in South Carolina. It belongs to the family Xenorophidae.
Pisco Basin is a sedimentary basin extending over 300 kilometres (190 mi) in southwestern Peru. The basin has a 2 kilometres (6,600 ft) thick sedimentary fill, which is about half the thickness of more northern foreland basins in Peru.
