Phacops Fossil Trilobite Arthropod Prehistoric Devonian Collection (4)

Description

Origin : Morocco (Erfoud - Hamar Laghdad Formation)

Geological era : Lower Devonian (Praghian)

Age : 410 million of years

Size : 88 gr - mm 58 x 47 x 26

Trilobite Sea Invertebrate Fossil mm 58 x 47 x 26 gr 88 Phacops (Eldredgeops) rana Arthropods Trilobitomorphs Phacopids Extinct Prehistoric Paleozoic Devonian Collecting Paleontology Museum.

Pleasant fossil find on matrix of Trilobite Phacopida from the Lower Devonian, representative collection specimen of best quality, in lying position, with clear details perfectly preserved of the trilobed metameric structure, head and pygidium.
Only a piece, as in photo.

Trilobites are marine Arthropods exclusive of Paleozoic era, lived by the Lower Cambrian (520-530 moy) to the late Permian (250 moy).
Their name means "three lobed", their most obvious morphological characteristic, the partition of the body into three longitudinal lobes: one axial lobe (center) and two pleural lobes (side). They are forms generally small to medium size from a few millimeters to about ten centimeters long, exceptionally up to some decimetres. Trilobites have an exoskeleton partly organic and partly composed of calcium carbonate. These animals have a head with compound eyes, a metameric segmented and articulated thorax and a rear shield pigidium. They also have a pair of jointed appendages on each segment of the body.
Up to date have been determined about 1,500 genera and 10,000 species of trilobites lived 270 million years in the overall life of this group. The trilobite are good fossil-guide, featuring a wide geographical spread, very important for the dating of the Paleozoic sedimentary rocks.

Phacops is a genus of Arthropod belonging to the extinct Trilobites. Its fossils have been found in the north-east of the United States, in south-west of Ontario and in Morocco, in soils from the Silurian to Devonian (430 million to 360 million years ago).
To recall in this regard that North America had joined the African plate during the Devonian.
This animal was one of the most typical and most common trilobites. Because of its abundance and popularity among collectors, the Phacops rana has been designated as the fossil of the State of Pennsylvania at General Assembly on 5 December 1988.
The body was oval in shape, with a large head (cephalon) and a little behind (pygidium). The central region of the head (glabella) was large and narrow posteriorly, adorned with numerous large granules that covered the entire surface. Eyes, often well preserved in fossils, are very large. At the hypostome (ventral plaque placed near the mouth) is originated two antennas uniramate. The characteristic "three lobes" body typical of the entire class sizes were very similar and well rounded.
Probably Phacops was able to swim like to go walking the seabed in search of food. In emergencies, the animal was able to roll up on itself, leaving only protrude the carapace hard and tough; this type of behavior is evident in the fossil, which bear on the ventral region of the cephalon a kind of groove that served to accommodate the rear of the pygidium when the animal is crumpled. Among the best known species, to remember Phacops rana (Eldredgeops rana) of the Lower Devonian.