''Chotecops'' is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of
trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the ...
s from the order
Phacopida
Phacopida ("lens-face") is an order of trilobites that lived from the Late Cambrian to the Late Devonian. It is made up of a morphologically diverse assemblage of taxa in three related suborders.
Characteristics
Phacopida had 8 to 19 thorac ...
, suborder
Phacopina
The Phacopina comprise a suborder of the trilobite order Phacopida. Species belonging to the Phacopina lived from the Lower Ordovician (Tremadocian) through the end of the Upper Devonian (Famennian).Moore, R.C. (ed.). Treatise on Invertebrate Pale ...
, family
Phacopidae
Phacopidae is a family of phacopid trilobites that ranges from the Lower Ordovician to the Upper Devonian, with representatives in all paleocontinents.
Description
As in all Phacopina, the eyes (if present) consist of very large (0.5 mm in ...
. It was initially erected as a subgenus of ''
Phacops
''Phacops'' is a genus of trilobites in the order Phacopida, family Phacopidae, that lived in Europe, northwestern Africa, North and South America and China from the Late Ordovician until the very end of the Devonian, with a broader time range ...
'' but some later authors thought it distinctive enough to raise its status. Species assigned to this genus occur between the
Emsian
The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 407.6 ± 2.6 million years ago to 393.3 ± 1.2 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after ...
and the
Famennian
The Famennian is the latter of two faunal stages in the Late Devonian Epoch. The most recent estimate for its duration estimates that it lasted from around 371.1 million years ago to 359.3 million years ago. An earlier 2012 estimate, still used ...
. ''Chotecops'' is the most abundant trilobite in the
Hunsrück Slate
The Hunsrück () is a long, triangular, pronounced upland in Rhineland-Palatinate, Germany. It is bounded by the valleys of the Moselle-Saar (north-to-west), the Nahe (south), and the Rhine (east). It is continued by the Taunus mountains, past t ...
and due to the excellent preservation, often soft tissue such as antennae and legs have been preserved as a thin sheet of pyrite.
Description
Like in all sighted
Phacopina
The Phacopina comprise a suborder of the trilobite order Phacopida. Species belonging to the Phacopina lived from the Lower Ordovician (Tremadocian) through the end of the Upper Devonian (Famennian).Moore, R.C. (ed.). Treatise on Invertebrate Pale ...
, the eyes of ''Chotecops'' are compounded of very large, separately set lenses without a common cornea (so called schizochroal eyes), and like almost all other Phacopina, the articulate mid-length part of the body (or
thorax
The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the ...
) in ''Chotecops'' has 11 segments.
The central raised area of the cephalon (called glabella) consists from back to front of an occipital ring, but unlike in its close relative ''
Phacops
''Phacops'' is a genus of trilobites in the order Phacopida, family Phacopidae, that lived in Europe, northwestern Africa, North and South America and China from the Late Ordovician until the very end of the Devonian, with a broader time range ...
'' the preoccipital ring in ''Chotecops'' is flat and not reduced to its sides, and the furrow defining its front (S1) is shallow. One or two pairs of furrows (S2 and S3) may be visible further to the front which are weak at best. The large frontal lobe is moderately vaulted and falls steeply to the furrow that defines the border at its front. The space between the glabella and the eyebrow (or palpebral area) is flat. The headshield has a finer sculpture. The tailshield (or
pygidium
The pygidium (plural pygidia) is the posterior body part or shield of crustaceans and some other arthropods, such as insects and the extinct trilobites. In groups other than insects, it contains the anus and, in females, the ovipositor. It is com ...
) is weakly furrowed. These characters distinguish it from ''Phacops''.
Some known species and locations.
Trilobites of the Hunsrück Slate, Germany
/ref>
* ''C. ferdinandi'' (Kayser, 1880), Hunsrück Germany.
* ''C. opitzi'' Struve, 1985, Hunsrück Germany.
* ''C. zofiae'' Chlupac, 1993, is known from the Middle or Upper Devonian of Poland (near the Givetian/Frasnian border, Holy Cross Mountains).
References
Phacopidae
Devonian trilobites of Europe
Fossils of Germany
Early Devonian first appearances
Famennian extinctions
Hunsrück Slate fossils
{{phacopida-stub