''Vetulicola rectangulata'' (meaning "rectangular ancient dweller") is a species of extinct animal from the Early

Cambrian The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

of the

Chengjiang biota The Maotianshan Shales () are a series of Early Cambrian sedimentary deposits in the Chiungchussu Formation or Heilinpu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized orga ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

. Regarded as a

deuterostome Deuterostomes (from Greek: ) are bilaterian animals of the superphylum Deuterostomia (), typically characterized by their anus forming before the mouth during embryonic development. Deuterostomia comprises three phyla: Chordata, Echinodermata, ...

, it has characteristic rectangular anterior body on which the posterior tail region is attached. It was described by Luo Huilin and Hu Shi-xue in 1999.

Description

''V. rectangulata'' was described by Luo Huilin and Hu Shi-xue of the Yunnan Institute of Biological Science in 1999. The fossils were discovered from the Early Cambrian Chengjiang deposits in Kunming region, Yunnan, China. Like ''V. cuneata,'' ''V. rectangulata'' has a body composed of two distinct parts of approximately equal length. The anterior part is oval to rectangular in shape, enclosed by a

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

-like structure of four rigid cuticular plates fused together, with a small mouth at the front end: there is a keel-like extension of the body wall on the top and belly. Unlike in ''V. cuneata'', the mouth region does not protrude out. The tail-like posterior section is slender, strongly cuticularised and placed

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

ly. Paired openings connecting the

pharynx The pharynx (: pharynges) is the part of the throat behind the human mouth, mouth and nasal cavity, and above the esophagus and trachea (the tubes going down to the stomach and the lungs respectively). It is found in vertebrates and invertebrates ...

to the outside run down the sides. These features are interpreted as possible primitive

gill slit Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In c ...

s. ''Vetulicola rectangulata'' could be up to 7.2 cm long, and up to 3.7 cm in height (most specimens being 3.6 cm high).

Lifestyle

It is assumed that ''V. rectangulata'' spent most or all of its time swimming in the water column. Sediment found within the gut suggest that it was a deposit-feeder, possibly swimming to and from favorable feeding sites. At least one specimen has an individual of the putative entoproct, '' Cotyledion tyloides'' attached to the terminal segment of the tail.

References

External links

Biota of the Maotianshan Shale, Chengjiang China
- URL retrieved June 22, 2006 *

Palaeos Palaeos.com is a web site on biology, paleontology, phylogeny and geology and which covers the history of Earth. The site is well respected and has been used as a reference by professional paleontologists such as Michael J. Benton, the professor of ...

' Page on

Vetulicolia Vetulicolia is a group of bilaterian marine animals encompassing several extinct species from the Cambrian, and possibly Ediacaran, periods. As of 2023, the majority of workers favor placing Vetulicolians in the stem group of the Chordata, but ...

br>Photos of ''Vetulicola cuneata'' fossils
- URL retrieved June 22, 2006 {{Taxonbar, from=Q17104101 Vetulicolia Fossil taxa described in 1999 Maotianshan shales fossils Cambrian China