''Fallotaspis'' is a genus of redlichiid

trilobites 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 At ...

found in Early Cambrian-aged strata of 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 territori ...

and

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria t ...

Etymology

The generic name, Fallotaspis, is a compound crassis word that honors Paul Fallot (1889-1960), a French

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

who researched Cambrian fossils in Spain, in combination with the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word ἀσπίς, ''aspis'', meaning shield.

Description

As with most early trilobites, ''Fallotaspis'' has an almost flat exoskeleton, that is only thinly calcified, and has crescent-shaped eye ridges. As part of the Olenellina suborder, ''Fallotaspis'' lacks dorsal sutures. As part of the superfamily Fallotaspidoidea ''Fallotaspis'' can be distinguished from

Olenelloidea The Olenelloidea are a superfamily of trilobites, a group of extinct marine arthropods. They lived during the late Lower Cambrian and species occurred on all paleocontinents. Taxonomy Palmer and Repina assigned '' Gabriellus'' and ''Callavi ...

Judomioidea The Judomioidea are a superfamily of trilobites, a group of extinct marine arthropods. Its species lived during the Lower Cambrian (Atdabanian Cambrian Stage 3 is the still unnamed third stage of the Cambrian. It succeeds Cambrian Stage 2 an ...

and Nevadioidea by features of the cephalon and in particular 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 to ...

. The glabella tapers forward. The frontal lobe of the glabella (because it is counted from the back, it is numbered L4) is as long as the most backward lobe (L0), less than in these other Olenellina subfamilies. The eye ridges (or ocular lobes) contact, but do not merge with, the entire frontal margin of the glabella. The cephalon of ''Fallotaspis'' is semi-circular in shape, with rounded cheeks that are continuous with long spines that go back to the first half of the thorax. Sutures absent. The

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 cre ...

has up to 21 segments. The third segment terminating in a long spine that extends back to the fourteenth segment. The tail shield (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 compo ...

) is very small, about the same length as the two most backward thorax segments combined.

Key to the species

This key is based on the analysis of Lieberman. This key only includes the two ''Fallotaspis'' species that Lieberman included in his analysis, where the literature suggests there may be at least ten species. It complements the key in the

Fallotaspidoidea The ”Fallotaspidoidea” are a superfamily of trilobites, a group of extinct marine arthropods. It lived during the Lower Cambrian (Atdabanian)Whittington, H. B. et al. Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Tril ...

article.

Sources

Photo of F. longa

References

{{Taxonbar, from=Q5432425 Fossils of Morocco Fallotaspidoidea Cambrian trilobites