''Conocoryphe'' is a genus of primarily eyeless

trilobite Trilobites (; meaning "three-lobed entities") are extinction, extinct marine arthropods that form the class (biology), class Trilobita. One of the earliest groups of arthropods to appear in the fossil record, trilobites were among the most succ ...

s belonging to the family Conocoryphidae. They lived during the Middle

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 ...

period, about 505 million years ago. These

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s lived on the sea bottom (

epifauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and ''funga'', respectively. Flora, fauna, funga and other forms of life are collectively r ...

l) and lived off dead particulate organic matter (a lifestyle called detritivorous).

Distribution

Cambrian of the Czech Republic, France, Spain, Turkey, United States (Wisconsin).

Taxonomy

''Conocephalites'' Barrande, 1852 was introduced as a replacement for ''Conocephalus'' Zenker, 1833, which was unavailable since Thunberg (1815 ) had previously used the name for a genus of conehead bushcricket. Barrande, however, was unaware that ''Conocoryphe'' had already been proposed by Hawle and Corda in 1847.

Type species

''Trilobites sulzeri'' (Schlotheim, 1823 = ''Conocoryphe sulzeri sulzeri'' (Schlotheim, 1823); ''Conocoryphe latifrons'' Hawle & Corda, 1847 HAWLE, I. and CORDA, A. J. C. 1847. Podrom einer Monographie der bo Èhmischen Trilobiten. ''Abhandlungen der Ko Èniglichen No Èhmischen Gesellschaft der Wissenschaften'', 5, 1-176.

Reassigned species

Some species, that were describe as belonging to ''Conocoryphe'' have since been classified in other genera. * ''C. kingii'' = ''

Elrathia kingii ''Elrathia'' is a genus of trilobite belonging to Ptychopariacea known from the mid-Cambrian of Laurentia (North America). ''E. kingii'' is one of the most common trilobite fossils in the USA locally found in extremely high concentrations withi ...

'' * ''C. rouayrouxi'' = '' Solenopleuropsis rouayrouxi'' * ''C. salteri'' = '' Leptoplastides salteri''

Description

''Conocoryphe'' is a rather flat trilobite of average size with an elongate oval outline. Overall shape of the

cephalon Cephalon, Inc. was an American biopharmaceutical company co-founded in 1987 by pharmacologist Frank Baldino Jr., Frank Baldino, Jr., neuroscientist Michael Lewis, and organic chemist James C. Kauer—all three former scientists with the DuPont ...

is semicircular. The

glabella The glabella, in humans, is the area of skin between the eyebrows and above the nose. The term also refers to the underlying bone that is slightly depressed, and joins the two brow ridges. It is a cephalometric landmark that is just superior ...

tapers forward, is defined by deep axial furrows, and has three pairs of lateral furrows that are directed backward and inward and which do not connect across the midline. The glabella is separated from the anterior margin by a very conspicuous narrow convex preglabellar field that is lower than and does not reach the adjacent fixigenae. Occipital ring is distinct. Without eyes but for one known exception. Eye ridges (when present) are threadlike, evenly curved, extending from anterior corners of the glabella to the genal angles. Anterior cephalic border furrow is deep, concave and wider than the narrow convex border itself. The lateral cephalic border is divided longitudinally by a suture and extends into slender, backward-directed genal spines. Genal spines extend to the 4th thorax segment, but are often broken off, even in well preserved specimens. The

hypostome In zoology, the hypostome can refer to structures in distinct animal groups: *Hypostome (trilobite), the ventral mouthpart plate in trilobites *Hypostome (tick) The hypostome (also called the maxilla, radula, or Labium (insect), labium) is a Os ...

is natant (or floating) i.e. not attached to the doublure and aligned with front edge of the glabella . The cephalic doublure and ventral sutures are not known.

Thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of 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 di ...

consists of 14 segments, with a rather narrow axis (of about 20% of the total width) that tapers evenly backwards. Deeply furrowed pleurae extend outward perpendicular to the axis and have rounded tips.

Pygidium The pygidium (: 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 compos ...

has 6 to 8 segments that are arched backward and become less well-defined towards posterior. The pygidium is semicircular in outline, its outer margin evenly curved, and it has a narrow, well-defined border. It is about half as wide as the cephalon (micropygous), and about half as long as wide.

Secondary sight

''Conocoryphe'' provides a rare (but not unique) example of secondary eye development. Conocoryphids lack eyes except for ''Conocoryphe oculata''. This species is otherwise very similar to its relatives from the Montagne Noir region in France. ''C. oculata'' has normal curving eye ridges, although the dorsal suture is marginal like in its blind family. Due to poor preservation, lenses have not been found. It seems that the expression of a gene for eye development was only suppressed and not lost, and the eye could develop when the suppression lifted.

References

External links

*
''Conocoryphe''
at insectoid.info {{Taxonbar, from=Q31290 Ptychopariida genera Cambrian trilobites Fossils of the Czech Republic Fossils of France Fossils of Spain Fossils of Turkey Fossils of the United States