| Taikicetus Temporal range: Middle Miocene, | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Genus: | † Taikicetus Tanaka, Ando, and Sawamura, 2018 |
| Species: | †T. inouei |
| Binomial name | |
| †Taikicetus inouei Tanaka, Ando, and Sawamura, 2018 | |
Taikicetus is a genus of basal thalassothere baleen whale from the Middle Miocene of Japan.
Phylogenetic analysis recovers Taikicetus as a basal thalassothere more primitive than Cetotheriidae and Balaenopteroidea. [1]
Taikicetus is distinguished from other closely related thalassotheres by an anteriorly swollen short zygomatic process (length vs width of the zygomatic process; high triangular coronoid process; and weak angular process, which does not reach as far posterior as the mandibular condyle; outline of suture between maxillae and palatines forming a posteriorly pointing V-shape, convex lateral edge of supraoccipital convex in dorsal view, tip of postglenoid process in lateral view pointing ventrally, and outline of postglenoid process distinctly wider than high in anterior or posterior view. [1]
In the human skull, the zygomatic bone, also called cheekbone or malar bone, is a paired irregular bone, situated at the upper and lateral part of the face and forming part of the lateral wall and floor of the orbit, of the temporal fossa and the infratemporal fossa. It presents a malar and a temporal surface; four processes, and four borders.
The radius or radial bone is one of the two large bones of the forearm, the other being the ulna. It extends from the lateral side of the elbow to the thumb side of the wrist and runs parallel to the ulna. The ulna is longer than the radius, but the radius is thicker. The radius is a long bone, prism-shaped and slightly curved longitudinally.
In anatomy, the masseter is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. The most obvious muscle of mastication is the masseter muscle, since it is the most superficial and one of the strongest.
In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery.
The condyloid process or condylar process is the process on the human and other mammalian species' mandibles that ends in a condyle, the mandibular condyle. It is thicker than the coronoid process of the mandible and consists of two portions: the condyle and the constricted portion which supports it, the neck.
The greater wing of the sphenoid bone, or alisphenoid, is a bony process of the sphenoid bone, positioned in the skull behind each eye. There is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backward.
The squamous part of temporal bone, or temporal squama, forms the front and upper part of the temporal bone, and is scale-like, thin, and translucent.
The tympanic part of the temporal bone is a curved plate of bone lying below the squamous part of the temporal bone, in front of the mastoid process, and surrounding the external part of the ear canal.
The zygomatic processes are three processes (protrusions) from other bones of the skull which each articulate with the zygomatic bone. The three processes are:
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.
Cetotheriidae is a family of baleen whales. The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by Fordyce & Marx 2013 recovered the living pygmy right whale as a member of Cetotheriidae, making the pygmy right whale the only living cetotheriid, other authors either dispute this placement or recover Neobalaenidae as a sister group to Cetotheriidae.
Peripolocetus is a genus of balaenid baleen whale from the middle Miocene of Kern County, California.
Nannocetus is an extinct baleen whale belonging to the family Cetotheriidae.
Eomysticetidae is a family of extinct mysticetes belonging to Chaeomysticeti. It is one of two families in the basal chaeomysticete clade Eomysticetoidea.
Tranatocetus is an extinct genus of mysticete from the late Miocene (Tortonian) of Jutland, Denmark. The type and only species is Tranatocetus argillarius.
Tokarahia is a genus of eomysticetid baleen whale from the Late Oligocene (Chattian) of New Zealand. There are two recognized species, T. kauaeroa and T. lophocephalus.
Brandtocetus is a genus of cetotheriid mysticete in the subfamily Cetotheriinae. The type and only species is Brandtocetus chongulek from the late Miocene (Tortonian) of the Kerch Peninsula in Crimea.
Zarhinocetus is an extinct genus of whale from the Early to Middle Miocene of the eastern North Pacific.
Waharoa is a genus of eomysticetid baleen whale from the Late Oligocene (Chattian) of New Zealand. It was identified with the discovery of Waharoa ruwhenua by Boessenecker and Fordyce (2015), which added a new genus and species to a monophyletic family Eomysticetidae.
Otradnocetus is an extinct genus of baleen whale from the middle Miocene of the Russian Caucasus.
