Krommaster | |
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Holotype specimen of K. spinosus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Ophiuroidea |
Family: | † Encrinasteridae |
Subfamily: | † Encrinasterinae |
Genus: | † Krommaster Reddy, Thuy, Reid & Gess, 2023 |
Species: | †K. spinosus |
Binomial name | |
†Krommaster spinosus Reddy, Thuy, Reid & Gess, 2023 | |
Krommaster (meaning "Krom River star") is an extinct genus of early ophiuroids (brittle stars [1] ) that lived nearly 410 million years ago in the early Devonian period of South Africa. It was found in the upper unit of the Baviaanskloof formation, Cape super group, Table Mountain group, Eastern cape. This genus has one species which is Krommaster spinosus. This species was discovered alongside Hexuraster , another species of brittle star living in the same area. [2]
Fossilized material of brittle stars were discovered in South African deposits older than the Bokkeveld Group for the first time by paleontologist Robert Gess, who collected several specimens originating from the upper unit of the Baviaanskloof Formation in Eastern Cape. These specimens were described in a 2023 study which recognized most of them to represent a new genus and species, while one of them was a specimen of Hexuraster weitzi. The new taxon was given the name Krommaster spinosus, the generic name combining "Kromm" (in reference to the Krom River, in the canyon of which the fossils were found) with the Latin word "aster" (meaning "star"), while the specific name is Latin for "spiny" (in reference to the animal's large spines). A fully articulated specimen and its counterpart (AM18222A+B) were designated as the holotype of this species, and two other specimens were listed as paratypes. These are all kept in the Albany Museum, along with two additional known specimens. [3]
This genus is characterized by their moderately large encrinasterid with a disk covered in a mosaic of small, thin scales and extending form the fifth and sixth arm segments. They also have conical pointed spines with similar but smaller spines on the dorsal disk and along the dorsal mid line of the arms. [3]
Lesothosaurus is a monospecific genus of ornithischian dinosaur that lived during the Early Jurassic in what is now South Africa and Lesotho. It was named by paleontologist Peter Galton in 1978, the name meaning "lizard from Lesotho". The genus has only one valid species, Lesothosaurus diagnosticus. Lesothosaurus is one of the most completely-known early ornithischians, based on numerous skull and postcranial fossils from the Upper Elliot Formation. It had a simpler tooth and jaw anatomy than later ornithischians, and may have been omnivorous in some parts of the year.
Brittle stars, serpent stars, or ophiuroids are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to 60 cm (24 in) in length on the largest specimens.
Bothriolepis was a widespread, abundant and diverse genus of antiarch placoderms that lived during the Middle to Late Devonian period of the Paleozoic Era. Historically, Bothriolepis resided in an array of paleo-environments spread across every paleocontinent, including near shore marine and freshwater settings. Most species of Bothriolepis were characterized as relatively small, benthic, freshwater detritivores, averaging around 30 centimetres (12 in) in length. However, the largest species, B. rex, had an estimated bodylength of 170 centimetres (67 in). Although expansive with over 60 species found worldwide, comparatively Bothriolepis is not unusually more diverse than most modern bottom dwelling species around today.
Groenlandaspis is an extinct genus of arthrodire from the Late Devonian. Fossils of the different species are found in late Devonian strata in all continents except eastern Asia. The generic name commemorates the fact that the first specimens of the type species were found in Greenland.
Hyposaurus is a genus of extinct marine dyrosaurid crocodyliform. Fossils have been found in Paleocene aged rocks of the Iullemmeden Basin in West Africa, Campanian–Maastrichtian Shendi Formation of Sudan and Maastrichtian through Danian strata in New Jersey, Alabama and South Carolina. Isolated teeth comparable to Hyposaurus have also been found in Thanetian strata of Virginia. It was related to Dyrosaurus. The priority of the species H. rogersii has been debated, however there is no sound basis for the recognition of more than one species from North America. The other North American species are therefore considered nomina vana.
Ophiocanops fugiens is a living species in the brittle star family Ophiocanopidae. Though once considered to be the only one living species in this brittle star family, recent research has brought to light three specimens of Ophiocanops that differ substantially from O. fugiens. It has been regarded as the most primitive brittle star, close to Paleozoic forms, though other authors have disagreed with the view. Classification of O. fugiens is highly argued. Ophiocanops is usually placed in the order Oegophiurida or regarded as a genus incertae sedis or even given its own subclass Oegophiuridea. Some recent data suggest its relationship to the extant family Ophiomyxidae.
Cruxicheiros is a genus of theropod dinosaur which lived in the Middle Jurassic of England. The type species is C. newmanorum, described by Roger Benson and Jonathan Radley in 2010.
The Kouga River originates near Uniondale, Eastern Cape, South Africa, and flows eastward, where it joins the Groot River to form the Gamtoos just past the Kouga Dam. Its main tributary is the Baviaanskloof River, which joins its left bank before the dam.
Asterotrygon is an extinct genus of stingray from the Eocene Green River Formation in Wyoming. Several complete skeletons representing juveniles, adults, males and females have been uncovered from the late early Eocene Fossil Butte Member of the formation. The type and only species, A. maloneyi, was named in 2004 on the basis of these fossils. Another stingray, Heliobatis, is also known from the formation. Asterotrygon is a primitive stingray closely related to the living family Urolophidae whose ancestors likely originated in the Indo-Pacific. It lived in Fossil Lake, a body of water that existed in a subtropical mountainous region for only about 2 million years.
Prolacerta is a genus of archosauromorph from the lower Triassic of South Africa and Antarctica. The only known species is Prolacerta broomi. Prolacerta was a small and slender reptile, with a rather long neck, low skull, and serrated teeth. It would have resembled a modern monitor lizard at a quick glance, though this is an example of convergent evolution as opposed to close affinities.
Gondwanascorpio emzantsiensis is an extinct Gondwanan scorpion that lived 360 million years ago in the Devonian. Its fossil remains, clearly showing pincer and sting, were discovered in rocks of the Witteberg Group near Grahamstown in South Africa. At present, this scorpion is the oldest known land-dwelling animal from Gondwana, which in Devonian times was separated from Laurasia by a deep ocean. At the time, the fossil site was only 15° from the South Pole, but rather than arctic-like tundra, the region was probably wooded, providing ample insect life for food. Previously, only two scorpion species were known from the late Devonian – Hubeiscorpio gracilitarsus from China and Petaloscorpio bureaui from Canada. The species was described by Robert Gess of Wits University in the journal African Invertebrates. The specific epithet derives from umZantsi, the isiXhosa word for "south", sometimes used for South Africa.
Priscomyzon riniensis is an extinct lamprey that lived some 360 million years ago during the Famennian in a marine or estuarine environment in South Africa. This small agnathan is anatomically similar to the Mazon Creek lampreys, but is some 35 million years older. Its key developments included the first known large oral disc, circumoral teeth and a branchial basket.
Galeamopus is a genus of herbivorous diplodocid sauropod dinosaurs. It contains two known species: Galeamopus hayi, known from the Late Jurassic lower Morrison Formation of Wyoming, United States, and Galeamopus pabsti, known from the Late Jurassic fossils from Wyoming and Colorado. The type species is known from one of the most well preserved diplodocid fossils, a nearly complete skeleton with associated skull.
Serenichthys kowiensis is a fossil species of coelacanth described in 2015 from near Grahamstown in South Africa.
Antarctilamna is an extinct genus of Devonian cartilaginous fish originally exemplified by Antarctilamna prisca from South Eastern Australia and Antarctica. The latest occurring described species is Antarctilamna ultima from the Waterloo Farm lagerstätte in South Africa. Antarctilamna has robust ctenacanthid-like spines which lack a deep insertion area, and are borne in front of the first dorsal fin; in addition to distinctive diplodont teeth with small intermediate cusps. Antarctilamna-like spines, known from the Bunga Beds locality in Australia have been ascribed to A. prisca.
Dwykaselachus is an extinct genus of symmoriiform, a cartilaginous fish that lived in what is now South Africa during the Permian period around 280 million years ago. It was first discovered in the 1980s, in a nodule of sediments from the Karoo Supergroup. Dwykaselachus was named based on Dwyka Group, the group of sedimentary geological formation in the southeastern part of Africa. It represents the place where the type species Dwykaselachus oosthuizeni was found.
Plesioselachus is an extinct genus of Late Devonian (Famennian) cartilaginous fish with uncertain classification, which contains only one species, P. macracanthus from the Waterloo Farm lagerstätte in South Africa. Known from a single incomplete articulated skeleton and some isolated remains, it is characterized by having a long dorsal spine with length about one third of body length.
The Waterloo Farm lagerstätte is a Famennian lagerstätte in South Africa that constitutes the only known record of a near-polar Devonian coastal ecosystem.
Diplacanthus is an extinct genus of Mid to Late Devonian fish in the class Acanthodii, known as spiny sharks.
Isityumzi mlomomde is fossil lungfish described from fragmentary remains including one complete parasphenoid, tooth plates fragments and scales from the Late Devonian Sarcopterygians. It represents the only record of Late Devonian lungfish remains from western Gondwana.