In paleontology, a zombie taxon [1] [2] (plural zombie taxa) or the zombie effect refers to a fossil that was washed out of sediments and re-deposited in rocks and/or sediments millions of years younger. [3] That basic mistake in the interpretation of the age of the fossil leads to its title, [4] in that the discovered fossil was at some point mobile (or "walking") despite the original organism having been long dead. When that occurs, the fossil is described as a "reworked fossil".
Nodosaurus is a genus of herbivorous nodosaurid ankylosaurian dinosaur from the Late Cretaceous, the fossils of which are found exclusively in the Frontier Formation in Wyoming.
Hypsilophodontidae is a traditionally used family of ornithopod dinosaurs, generally considered invalid today. It historically included many small bodied bipedal neornithischian taxa from around the world, and spanning from the Middle Jurassic until the Late Cretaceous. This inclusive status was supported by some phylogenetic analyses from the 1990s and mid 2000s, although there have also been many finding that the family is an unnatural grouping which should only include the type genus, Hypsilophodon, with the other genera being within clades like Thescelosauridae and Elasmaria. A 2014 analysis by Norman recovered a grouping of Hypsilophodon, Rhabdodontidae and Tenontosaurus, which he referred to as Hypsilophodontia. All other analyses from around the same time have instead found these latter taxa to be within Iguanodontia.
Agnosphitys is a genus of dinosauriform that lived during the Late Triassic. It contains only one species, the type species A. cromhallensis. Its remains include an ilium, maxilla, astragalus and humerus, which date variously from the Norian and Rhaetian stages of the Late Triassic, or possibly as late as the Hettangian stage of the Early Jurassic. The fissure fill at Avon, of which Agnosphitys was probably recovered from, was a sinkhole formed by the dissolution of Lower Carboniferous limestones.
Anoplosaurus is an extinct genus of herbivorous nodosaurid dinosaur, from the late Albian-age Lower Cretaceous Cambridge Greensand of Cambridgeshire, England. It has in the past been classified with either the armored dinosaurs or the ornithopods, but current thought has been in agreement with the "armored dinosaur" interpretation, placing it in the Ankylosauria.
Texasetes is a genus of ankylosaurian dinosaurs from the late Lower Cretaceous of North America. This poorly known genus has been recovered from the Paw Paw Formation near Haslet, Tarrant County, Texas, which has also produced the nodosaurid ankylosaur Pawpawsaurus.
Saurischia is one of the two basic divisions of dinosaurs, classified by their hip structure. Saurischia and Ornithischia were originally called orders by Harry Seeley in 1888 though today most paleontologists classify Saurischia as an unranked clade rather than an order.
Cedrorestes is a genus of iguanodontian dinosaur from the Early Cretaceous of Utah. It is based on an incomplete skeleton which was found in the Valanginian-age Yellow Cat Member of the Cedar Mountain Formation.
The Twin Mountains Formation, also known as the Twin Mak Formation, is a sedimentary rock formation, within the Trinity Group, found in Texas of the United States of America. It is a terrestrial formation of Aptian age, and is notable for its dinosaur fossils. Dinosaurs from this formation include the large theropod Acrocanthosaurus, the sauropod Sauroposeidon, as well as the ornithopods Tenontosaurus and Convolosaurus. It is the lowermost unit of the lower Cretaceous, lying unconformably on Carboniferous strata. It is overlain by the Glen Rose Formation. It is the lateral equivalent of the lower part of the Antlers Formation.
The Bushveld Sandstone is a geological formation dating to roughly between 201 and 189 million years ago and covering the Carnian to Norian stages. The Bushveld Sandstone is found in Transvaal, South Africa, and is a member of the Stormberg Group. As its name suggests, it consists mainly of sandstone. Fossils of the prosauropod dinosaur Massospondylus have been recovered from the Bushveld Sandstone.
The Bauxite of Cornet is a geological formation in Romania whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. It exists as karstic sediments infilling fissures and caves in limestone.
The Tugulu Group is a geological Group in Xinjiang, China whose strata date back to the Early Cretaceous. Dinosaur skeletal remains and footprints are among the fossils that have been recovered from the formation.
The Mooreville Chalk is a geological formation in North America, within the U.S. states of Alabama and Mississippi, which were part of the subcontinent of Appalachia. The strata date back to the early Santonian to the early Campanian stage of the Late Cretaceous. The chalk was formed by pelagic sediments deposited along the eastern edge of the Mississippi embayment. It is a unit of the Selma Group and consists of the upper Arcola Limestone Member and an unnamed lower member. Dinosaur, mosasaur, and primitive bird remains are among the fossils that have been recovered from the Mooreville Chalk Formation.
La Bocana Roja Formation is a geological formation in Baja California, Mexico whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.
The Trichinopoly Group is a geological formation in India whose strata date back to the Late Cretaceous. It lies between the Ootatoor and Ariyalur Groups. It is broad in its southern extremity but thins as it gradually proceeds northwards as it ultimately meets the Ariyalur Group. Dinosaur remains are among the fossils that have been recovered from the formation.
The Futaba Group is a Late Cretaceous geologic group in Japan. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. It consists of both fluvial and shallow marine sediments. The plesiosaur Futabasaurus was found in this unit.
The Gokwe Formation is an Early Cretaceous geologic formation in Zimbabwe. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. Sediments of the formation may have been laid down in a small shallow lake, carried by intermittent floods from a land surface surrounding the lake on which aeolian transport of sand took place. More likely the animals died on a dry lake bed, and their bones were exposed to a period of desiccation, later floods would scatter the fragments and incorporate them in sediment.
The Moenave Formation is a Mesozoic geologic formation, in the Glen Canyon Group. It is found in Utah and Arizona.
The Lianmuqin Formation, also transcribed as Lianmugin Formation, and Lianmuxin Formation, is an Early Cretaceous geologic formation composed of "interbedded red green and yellow variegated mudstones and siltstones". Dinosaur remains have been recovered from it.
The Pietraroia Plattenkalk is a Cretaceous geologic formation located in the Italian municipality of Pietraroja, near Benevento, in Campania region. It is of Albian age. Dinosaur remains diagnostic to the genus level are among the fossils that have been recovered from the formation and the type locality of the formation is the La Cavere quarry, which is near the village of Pietraroja.
The Khodzhakul Formation is a Cenomanian aged geologic formation in Uzbekistan. Dinosaur remains are among the fossils that have been recovered from the formation. As well as those of Mammals. It is part of the same stratigraphic succession as the overlying Bissekty Formation.