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.
Reptiliomorpha is a clade containing the amniotes and those tetrapods that share a more recent common ancestor with amniotes than with living amphibians (lissamphibians). It was defined by Michel Laurin (2001) and Vallin and Laurin (2004) as the largest clade that includes Homo sapiens, but not Ascaphus truei. Laurin and Reisz (2020) defined Pan-Amniota as the largest total clade containing Homo sapiens, but not Pipa pipa, Caecilia tentaculata, and Siren lacertina.
Anthracosauria is an order of extinct reptile-like amphibians that flourished during the Carboniferous and early Permian periods, although precisely which species are included depends on one's definition of the taxon. "Anthracosauria" is sometimes used to refer to all tetrapods more closely related to amniotes such as reptiles, mammals, and birds, than to lissamphibians such as frogs and salamanders. An equivalent term to this definition would be Reptiliomorpha. Anthracosauria has also been used to refer to a smaller group of large, crocodilian-like aquatic tetrapods also known as embolomeres.
The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 346.7 to 330.9 Ma. It follows the Tournaisian age/stage and is followed by the Serpukhovian age/stage.
Crassigyrinus is an extinct genus of carnivorous stem tetrapod from the Early Carboniferous Limestone Coal Group of Scotland and possibly Greer, West Virginia.
Pholiderpeton is an extinct genus of embolomere amphibian which lived in the Late Carboniferous period (Bashkirian) of England. The genus was first named by Thomas Henry Huxley in 1869 to include the species P. scutigerum, based on the disarticulated front half of a skeleton discovered near Bradford, Yorkshire. Associated fossil wood suggests that this specimen died inside a Lepidodendron tree trunk.
Anthracosaurus is an extinct genus of embolomere that lived during the Late Carboniferous in what is now Scotland, England, and Ohio. Measuring around 10 ft (3.0 m) long, it was a large, aquatic eel-like predator. It has a robust skull about 40 centimetres (1.3 ft) in length with large teeth in the jaws and on the roof of the mouth. Anthracosaurus probably inhabited swamps, rivers and lakes. Its name is Greek for "coal lizard".
Pteroplax is an extinct genus of embolomerous anthracosaur. Only one species has been described; the skull table noted is the lectotype of this species. Pteroplax dates from the late Carboniferous Period, about 315 million years ago. It is known with certainty only from Newsham in Blyth, Northumberland, England. At that site, it shared a coal-swamp lake habitat with the larger embolomere, "Eogyrinus". Pteroplax probably grew up to about 10 ft (3.0 m) in length and was largely aquatic, feeding upon fish and smaller tetrapods. It likely had a long, eel-like body, with short limbs and a long tail.
Adelospondylus is an extinct adelospondyl tetrapodomorph from the Carboniferous of what is now Scotland.
Spathicephalus is an extinct genus of stem tetrapods that lived during the middle of the Carboniferous Period. The genus includes two species: the type species S. mirus from Scotland, which is known from two mostly complete skulls and other cranial material, and the species S. pereger from Nova Scotia, which is known from a single fragment of the skull table. Based on the S. mirus material, the appearance of Spathicephalus is unlike that of any other early tetrapod, with a flattened, square-shaped skull and jaws lined with hundreds of very small chisel-like teeth. However, Spathicephalus shares several anatomical features with a family of stem tetrapods called Baphetidae, leading most paleontologists who have studied the genus to place it within a larger group called Baphetoidea, often as part of its own monotypic family Spathicephalidae. Spathicephalus is thought to have fed on aquatic invertebrates through a combination of suction feeding and filter feeding.
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.
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.
Spondylerpeton is an extinct genus of embolomere closely related to "Cricotus" (Archeria) in the family Archeriidae. This genus is known from fragmentary remains, namely a short series of tail vertebrae preserved in an ironstone nodule. These remains were found in the Mazon Creek beds of Illinois, an area famed for its preservation of Carboniferous plants and animals. Spondylerpeton individuals were probably about three to four feet in length, by far the largest animals known to have inhabited the Mazon Creek area during this era.
Stan Wood was a self-taught fossil hunter known for his significant palaeontological discoveries at scale and is arguably most celebrated for refocusing attention on early Carboniferous palaeobiology as the means to closing Romer's gap.
Papposaurus is an extinct genus of proterogyrinid embolomere which lived in the Mississippian of Scotland. It is known from a single species, Papposaurus traquiairi, which is based on an isolated femur discovered in ironstone near Loanhead. Though originally compared closely to reptiles, subsequent study has revealed closer similarity to basal embolomeres such as Proterogyrinus and Archeria. With such limited remains, Papposaurus may not be a valid genus. The femur was redescribed in 1986 by T. R. Smithson, who considered Papposaurus traquairi a nomen vanum possibly synonymous with Proterogyrinus scheelei.
Palaeoherpeton is an extinct genus of eogyrinid embolomere which lived in the Pennsylvanian of Scotland. It is primarily known from a series of relatively small but well-preserved skulls. Some of these have among the best braincase and middle ear material known in embolomeres. Originally given the species name Palaeogyrinus decorus, this was later corrected to Palaeoherpeton decorum when it was determined that Palaeogyrinus was a name preoccupied by a genus of beetles.
The Scottish Coal Measures Group is a lithostratigraphic unit referring to the coal-bearing succession of rock strata which occur in Scotland during the Westphalian regional stage of the Carboniferous Period. It is the Scottish portion of the informal Coal Measures Group, which also includes the South Wales and Pennine coal measures. The Scottish coal measures are well-exposed across the Midland Valley. The group is also found within small grabens in the vicinity of Sanquhar and Thornhill.
