Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish. Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms.
Placodus is an extinct genus of marine reptiles belonging to the order Placodontia, which swam in the shallow seas of the middle Triassic period. Fossils of Placodus have been found in Central Europe and China.
Placodonts are an extinct order of marine reptiles that lived during the Triassic period, becoming extinct at the end of the period. They were part of Sauropterygia, the group that includes plesiosaurs. Placodonts were generally between 1 and 2 m in length, with some of the largest measuring 3 m (9.8 ft) long.
Azendohsaurus is an extinct genus of herbivorous archosauromorph reptile from roughly the late Middle to early Late Triassic Period of Morocco and Madagascar. The type species, Azendohsaurus laaroussii, was described and named by Jean-Michel Dutuit in 1972 based on partial jaw fragments and some teeth from Morocco. A second species from Madagascar, A. madagaskarensis, was first described in 2010 by John J. Flynn and colleagues from a multitude of specimens representing almost the entire skeleton. The generic name "Azendoh lizard" is for the village of Azendoh, a local village near where it was first discovered in the Atlas Mountains. It was a bulky quadruped that unlike other early archosauromorphs had a relatively short tail and robust limbs that were held in an odd mix of sprawled hind limbs and raised forelimbs. It had a long neck and a proportionately small head with remarkably sauropod-like jaws and teeth.
Placochelys is an extinct genus of placodont reptiles erected by Otto Jaekel in 1902.
Cyamodus is a genus of placodonts known from several species described from Middle-Late Triassic of Europe and China. The genus was described by Christian Erich Hermann von Meyer in 1863, based on specimens found in Germany. Like some other placodonts, Cyamodus has an armoured carapace composed of irregular hexagonal plates, with the mouth containing a small number of large, rounded teeth that were likely involved in crushing hard shelled organisms (durophagy).
Psephoderma is a genus of placodonts very similar to the related genera Placochelys and Cyamodus. Psephoderma had a flattened skull and a narrow, straight rostrum, much narrower than that of its relatives. Inside this skull, embedded in the jaws, were rounded teeth specialized for crushing the shellfish it ate. Unlike henodontid placodonts, Psephoderma's carapace was divided into two pieces, one on the shoulders and back, and another on the ventral end. Psephoderma grew to 180 centimetres (5.9 ft) long, larger than many of its relatives, and lived in the Late Triassic, about 210 million years ago. It was one of the last placodonts to live. Fossils of Psephoderma have been found in the Rhaetian deposits in the Alps and in England, hence the specific names.
Doswellia is an extinct genus of archosauriform from the Late Triassic of North America. It is the most notable member of the family Doswelliidae, related to the proterochampsids. Doswellia was a low and heavily built carnivore which lived during the Carnian stage of the Late Triassic. It possesses many unusual features including a wide, flattened head with narrow jaws and a box-like rib cage surrounded by many rows of bony plates. The type species Doswellia kaltenbachi was named in 1980 from fossils found within the Vinita member of the Doswell Formation in Virginia. The formation, which is found in the Taylorsville Basin, is part of the larger Newark Supergroup. Doswellia is named after Doswell, the town from which much of the taxon's remains have been found. A second species, D. sixmilensis, was described in 2012 from the Bluewater Creek Formation of the Chinle Group in New Mexico; however, this species was subsequently transferred to a separate doswelliid genus, Rugarhynchos. Bonafide Doswellia kaltenbachi fossils are also known from the Chinle Formation of Arizona.
Omphalosaurus is an extinct genus of marine reptile from the Early Triassic to Middle Triassic, thought to be in the order of Ichthyosauria. Most of what is known about Omphalosaurus is based on multiple jaw fragments, ribs, and vertebrae. Specimens of Omphalosaurus have been described from the western United States, Poland, Austria and the island of Spitsbergen off the northern coast of Norway.
Thalattosaurus meaning "sea lizard," from the Attic Greek thalatta (θάλαττα), "sea," and sauros (σαῦρος), "lizard," is an extinct genus of marine reptile in the family Thalattosauroidea. They were aquatic diapsids that are known exclusively from the Triassic period. It was a 2–3 metres (6.6–9.8 ft) long shellfish-eating reptile with paddle-like limbs and a down-turned rostrum occurring in the Lower and Middle Triassic Sulphur Mountain Formation of British Columbia as well as the Upper Triassic Hosselkus Limestone of California. It has gained notoriety as a result of studies on general diapsid phylogeny.
Nanchangosaurus is an extinct genus of aquatic reptiles native to the middle Triassic of China. It was named after the area in China, Nanchang, where it was found. It was about more than 40 cm (16 in) in length, and probably fed on fish or used its long jaws to probe for aquatic invertebrates. It resembled the ichthyosaurs in build, and may be related to them.
Henodus is an extinct placodont of the Late Triassic period during the early Carnian age. Fossils of Henodus chelyops were found in the Estherienschichten Member of the Grabfeld Formation, near Tübingen, Germany. It was around 1 metre (3.3 ft) in length. The single species within the genus is H. chelyops.
Teraterpeton is an extinct genus of trilophosaurid archosauromorphs. It is known from a partial skeleton from the Late Triassic Wolfville Formation of Nova Scotia, described in 2003. It has many unique features seen in no other related form, including an elongated, toothless snout and large openings for the nostrils. Because of this, Teraterpeton was originally placed in its own family, Teraterpetidae, related to Trilophosaurus. Newer studies generally place it within Trilophosauridae.
Glyphoderma is an extinct genus of placodont reptile from the Middle Triassic of China with two known species, G. kangi and G. robusta. It differs from its relative Psephochelys in having three, rather than one, fused osteoderms on the posterior skull surface, and has an earlier temporal range, from the Ladinian epoch rather than the Late Triassic. Otherwise, it is similar in most respects to the other plachochelyids found in China. The name comes from the Greek 'γλυφος', 'sculpture' and 'δερμα', 'skin' referring to its unique carapace structure. The specific name honours a Mr. Kang Ximin.
Cyamodontoidea is an extinct superfamily of placodont marine reptiles from the Triassic period. It is one of the two main groups of placodonts, the other being Placodontoidea. Cyamodontoids are distinguished from placodontoids by their large shells, formed from fused bony plates called osteoderms and superficially resembling the shells of turtles. Cyamodontoids also have distinctive skulls with narrow, often toothless jaws and wide, flaring temporal regions behind the eyes. Two large temporal openings are positioned at the top of the back of the skull, an arrangement that is known as the euryapsid condition and seen throughout Sauropterygia, the marine reptile group to which placodonts belong. Cyamodontoids are also distinguished by their large crushing teeth, which grow from the palatine bones on the roof of the mouth.
Psephosauriscus is an extinct genus of placodont reptile from the Middle Triassic of Israel and Egypt. It is known from bony armor plates that have been found from Makhtesh Ramon in Israel's Negev desert and Araif en Naqua on Egypt's Sinai Peninsula. The genus was erected in 2002 as a replacement name for several species of the genus Psephosaurus, which was named in 1957. It includes the species P. mosis, P. ramonensis, P. sinaiticus, and a possible fourth species, P. rhombifer. All species, with the exception of P. ramonensis, were once assigned to the genus Psephosaurus. Remains of P. mosis and P. ramonensis were found in Makhtesh Ramon, while P. sinaiticus and P. rhombifer were found in Araif en Naqua.
Macroplacus is an extinct genus of placodont reptiles. The type species is M. raeticus and the fossil record of this species dates back to the upper Triassic, Rhaetian age. These fossils have been found in Germany, at Hinterstein near Hindelang im Allgäu.
Palatodonta is an extinct genus of neodiapsid reptile known from the early Middle Triassic of the Netherlands. It was initially described in 2013 as a basal placodontiform closely related to a group of marine reptiles called placodonts, characterized by their crushing teeth and shell-like body armor. Under this interpretation, Palatodonta is transitional between placodonts and less specialized reptiles. Like placodonts, it has a row of large teeth on its palate, but while these teeth are thick and blunt in placodonts, Palatodonta has palatal teeth that are thin and pointed. A 2023 study instead classified it as a sauropterygomorph and the sister taxon to Eusaurosphargis. In other words, it is close to, but not within, Sauropterygia.
Jaxtasuchus is an extinct genus of armored doswelliid archosauriform reptile known from the Middle Triassic of the Erfurt Formation in Germany. The type species, Jaxtasuchus salomoni, was named in 2013 on the basis of several incomplete skeletons and other isolated remains. Like other doswelliids, members of the genus were heavily armored, with four longitudinal rows of bony plates called osteoderms covering the body. Jaxtasuchus is the first doswelliid known from Europe and is most closely related to Doswellia from the Late Triassic of the eastern United States. However, it was not as specialized as Doswellia, retaining several generalized archosauriform characteristics and having less armor. Jaxtasuchus fossils have been found in aquatic mudstones alongside fossils of temnospondyl amphibians, crustaceans, and mollusks, suggesting that Jaxtasuchus was semiaquatic like modern crocodilians.
Atopodentatus is an extinct genus of basal sauropterygian known from the early Middle Triassic (Anisian) of Guanling Formation in Luoping County, Yunnan Province, southwestern China. It contains a single species, Atopodentatus unicus. It is thought to have lived between 247 and 240 million years ago, during the Middle Triassic period, about six million years after the Permian extinction. Atopodentatus was an herbivorous marine reptile, although marine reptiles are usually omnivores or carnivores.
