Bellacartwrightia calderonae

Table of Contents

Scientific Classification


Kingdom: Animalia
Phylum: Arthropoda
Class: Trilobita
Order: Phacopida
Family: Acastidae
Genus: Bellacartwrightia
Species: Bellacartwrightia calderonae Lieberman and Kloc, 1997

Information

Geological Range

Middle Devonian

Paleogeographic Distribution

New York

Stratigraphic Occurrences

Moscow Formation

Windom Member

Ludlowville Formation

References

Lieberman and Kloc (1997): Evolutionary and biogeographic patterns in the Asteropyginae (Trilobita, Devinian) Delo, 1935. in Bulletin of the American Museum of Natural History. American Museum of Natural History, pp. 51, 52.

Bignon and Cronier (2014): The systematics and phylogeny of the Devonian subfamily Asteropyginae (Trilobita: Phacopida). Journal of Systematic Palaeontology 12:pp. 637-668.

Remarks

Description: From Lieberman and Kloc (1997): “Cephalic length (sag.) 45% of width (tr.). Axial furrows nearly straight anterior to S1, diverging forward at about 350, narrow, shallow; posterior to S1 diverging at 100; diverging less strongly opposite anterior half of L3 than opposite posterior half. Frontal lobe about 50% of length of glabella, anterior margin smoothly rounded. PMI developed as rounded depression. LO 45% of width of frontal lobe. Large Eye Index 0.45. Anterior edge of eye contacts axial furrow opposite anterodistal corner of L3. S2 weakly declined posteriorly at lateral edges; S1 medially developed as straight line directed anteriorly. Maximum of eight lenses per dorsoventral file on visual surface; posterior edge of eye anterior to transverse line tangent to anterior edge of LO. Fixigena with bulge medially. Line from posterior to anterior edges of eye forms 5-10 degree angle with sagittal line. Lateral margin of genal spine at posterior end straight. Tubercle on LO. Tubercle on thoracic axial rings. Circular fenestrae on thoracic pleural bands and axial rings absent. Medial tubercle on pygidial axial rings. Axis constricts posterior to seventh axial ring. Laterally pygidial interpleural furrows flex more strongly posteriorly.”