Jennifer Alice Clack, was an English palaeontologist and evolutionary biologist. She specialised in the early evolution of tetrapods, specifically studying the "fish to tetrapod" transition: the origin, evolutionary development and radiation of early tetrapods and their relatives among the lobe-finned fishes. She is best known for her book Gaining Ground: the Origin and Early Evolution of Tetrapods, published in 2002 and written with the layperson in mind.
Tristychius is an extinct genus of euselachian chondrichthyan from the Carboniferous period (Visean). Fossils of T. arcuatus, the type and only species, including fin spines have been found in Scotland.
Cheirolepis is an extinct genus of marine and freshwater ray-finned fish that lived in the Devonian period of Europe and North America. It is the only genus yet known within the family Cheirolepididae and the order Cheirolepidiformes. It was among the most basal of the Devonian actinopterygians and is considered the first to possess the "standard" dermal cranial bones seen in later actinopterygians.
Canobius is an extinct genus of early marine ray-finned fish that lived in the early Carboniferous period (Viséan) of Glencartholm, Scotland.
Silvanerpeton is an extinct genus of early reptiliomorph found by Stan Wood in the East Kirkton Quarry of West Lothian, Scotland, in a sequence from the Brigantian substage of the Viséan. The find is important, as the quarry represents terrestrial deposits from Romer's gap, a period poor in fossils where the higher groups "labyrinthodonts" evolved.
Birgeria is a genus of carnivorous marine ray-finned fish from the Triassic period. Birgeria had a global distribution, with fossil known from Madagascar, Spitsbergen, Germany, Switzerland, Italy, Slovenia, China, Russia, Canada and Nevada, United States. The oldest fossils are from Griesbachian aged beds of the Wordie Creek Formation of East Greenland. Birgeria existed throughout the entire Triassic period, from the very beginning just after the Permian-Triassic mass extinction, up to the very end with its extinction during the Triassic-Jurassic mass extinction.
Elpistostegalia is a clade containing Panderichthys and all more derived tetrapodomorph taxa. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, such as Tiktaalik, are sometimes called fishapods. Although historically Elpistostegalia was considered an order of prehistoric lobe-finned fishes, it was cladistically redefined to include tetrapods.
Chondrenchelys is an extinct genus of cartilaginous fish and the earliest member of Holocephali known from complete skeletons. Chondrenchelys would have been quite a relatively medium-sized fish with an elongated body up to 18 cm (0.59 ft)in length, it had a dorsal fin which was indeed long and a body which tapered to a point. Chondrenchelys had one large pair, one middle-sized pair, and three small pair of tooth plates in each jaw.
Acestrus is an extinct genus of prehistoric marine ray-finned fish that lived during the lower Eocene in Europe. It contains one species, A. ornatus from the London Clay, known from a single braincase. It is thought to possibly be closely allied with billfish based on the braincase morphology, although it remains uncertain whether it had the rostrum characteristic of billfishes. Some authorities have suggested blochiid affinities.
Styracopterus is an extinct genus of prehistoric bony fish that lived during the Tournaisian stage of the Mississippian epoch of Scotland and Eastern European Platform, Russia.
Cheirodopsis is an extinct genus of prehistoric marine ray-finned fish that lived during the Viséan stage of the Mississippian epoch. It contains a single species, C. geikiei from what is now Glencartholm, Scotland.
Aetheretmon is an extinct genus of prehistoric freshwater and estuarine ray-finned fish that lived during the early Mississippian (Dinantian) age in what is now Europe, including Scotland, Belarus, and Russia. It contains only the species A. valentiacum. This genus has the oldest known actinopterygian growth series, indicating that juvenile Aetheretmon had tails similar to those of modern teleosts, but unlike teleosts, their upper tails continued to grow throughout their lives instead of truncating early. Initially classified as a "palaeoniscid", later studies have recovered it as a stem-neopterygian, or more recently a stem-actinopteran.
Bendenius is an extinct genus of prehistoric marine ray-finned fish. It is known from the Early Carboniferous of Belgium. It was named after Belgian paleontologist Pierre-Joseph van Beneden.
Cycloptychius is an extinct genus of prehistoric freshwater & marine ray-finned fish that existed throughout much of the Carboniferous period in Eurasia, and possibly into the Early Permian in South Africa. It was a member of the Rhadinichthyidae, a family of basal ray-finned fish that was formerly placed in the now-paraphyletic order Palaeonisciformes.
Strepheoschema is an extinct genus of prehistoric bony fish that lived during the early Mississippian (Tournaisian–Visean) in what is now Berwickshire, Scotland, and Northumberland, England. Fossils were recovered from the Ballagan Formation.
Mimipiscis is a fossil genus of very primitive ray-finned fishes from the Upper Devonian Gneuda and Gogo formations of Western Australia.
Phanerosteon is an extinct genus of prehistoric bony fish from the Carboniferous period. The type species, P. mirabile, was recovered from the Calciferous sandstone series (Pennsylvanian), Scotland. A second species, P. phonax was described from the Serpukhovian aged Bear Gulch Limestone lagerstätte in Montana, United States.
East Kirkton Quarry, or simply East Kirkton, is a former limestone quarry in West Lothian, Scotland, now a renowned fossil site. The quarry is known for terrestrial and freshwater fossils about 335 million years old, from the late Viséan stage of the Mississippian subperiod. The quarry is a 200-meter-long (~650 ft) depression located in the town of Bathgate. Geographically, it sits at the Bathgate Hills near the center of the Midland Valley, a fossil-rich region of southeast Scotland. The site is dominated by volcanic tuff, limestone, and silica deposits of large freshwater lakes associated with hot springs and local basaltic (high-iron) volcanism. Three geological intervals are exposed: the East Kirkton Limestone (oldest), Little Cliff Shale (middle), and Geikie Tuff (youngest).
Eldeceeon is an extinct genus of reptiliomorph from the Mississippian of Scotland. It is known from two fossil specimens found within the Viséan-age East Kirkton Quarry in West Lothian. The type and only species, E. rolfei, was named in 1994. Eldeceeon is thought to be closely related to embolomeres, but it has several distinguishing features including long limbs and a short trunk. Initially known from two crushed partial skeletons, additional specimens have been reported by Ruta & Clack (2006). Eldeceeon was redescribed by Ruta, Clack, & Smithson (2020). The redescription supported affinities with Silvanerpeton, reconstructed a skull with larger eyes and a shorter snout, and emphasized potential correlations for an enlarge puboischiofemoralis internus 2 muscle.
The Ballagan Formation is a geologic formation in Scotland and England. It preserves fossils dating back to the early part of the Carboniferous period. Its name comes from the "Ballagan Beds" of Ballagan Glen, near Strathblane, which has a good example of this geological formation.
