''Kouphichnium'' is an

ichnogenus An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

that has been attributed to limulids (horseshoe crabs). ''Kouphichnium'' fossils resemble the

footprint Footprints are the impressions or images left behind by a person walking or running. Hoofprints and pawprints are those left by animals with hooves or paws rather than feet, while "shoeprints" is the specific term for prints made by shoes. The ...

s of birds, sometimes in conjunction with a medial line, and were initially thought to be bird or

pterosaur Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...

tracks. The footprints are now believed to be the imprints of specialized limulid

appendage An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body. In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including anten ...

s, called pushers, terminating in four plates, used to push against the sediment. The medial line is left by the animal's

telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...

. This ichnogenus is registered in the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

to the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

, in marine marginal environments in

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...

, the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and in

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...

, as well as non-marine environments of

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

, among others.Aceñolaza, F. G., & Buatois, L. A. (1991). Trazas fósiles del Paleozoico superior continental argentino.
Ameghiniana
', 28, 89-108. The genus contains five species, ''K. arizonae'', ''K. cordifomnis'', ''K. lithographicum'', ''K. minusculum'' and ''K. walchi''.

References

Arthropod trace fossils {{trace-fossil-stub

See also

References