Weeksina

{{Short description|Genus of trilobites}} {{Automatic taxobox | fossil_range = {{Geological range|501|497|[[Dresbachian]]}}<ref name="Sepkoski">{{cite journal|last= Sepkoski|first= Jack|author-link = Jack Sepkoski |title= A compendium of fossil marine animal genera (Trilobita entry)|journal= Bulletins of American Paleontology|volume = 363|pages = 1–560|year= 2002|url= http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=307&rank=class|access-date= 2008-01-12}}</ref> | taxon = Weeksina | authority = Resser, 1935 | subdivision_ranks = Species | subdivision = {{Species list |Weeksina unispina|([[Charles Doolittle Walcott|Walcott]], 1916) ([[Type (biology)|type]]) [[Synonym (taxonomy)|=]] ''Asaphiscus unispinus'' }} }}

'''''Weeksina''''' is a [[genus]] of [[trilobite]]s, an extinct group of [[Marine habitats|marine]] [[arthropod]]s. It lived during the [[Dresbachian]] [[faunal stage]] of the late [[Cambrian Period]] which lasted from 501 to 490 million years ago. Its calcified [[Anatomical terms of location#Dorsal and ventral|dorsal]] [[exoskeleton]] has an inverted egg-shape. Characteristics of this trilobite are the backward directed spine on the 8th of 10 segment of the articulated middle part of the body (or [[Trilobite#Thorax|thorax]]), and the second pair of furrows from the back on the raised central part of the headshield (or [[Trilobite#Cephalon|cephalon]]) called glabella, which curve from inward to fully backward, almost isolating a pair of lobes, just in front of the occipital ring, that is defined by a furrow that crosses the entire width of the glabella. ''Weeksina'' is known only from the Weeks Formation at North Canyon, House Range, Millard County, Utah.<ref>{{cite journal|first= S.E.|last= Peters|year= 2003|title= Evenness, Richness and the Cambrian-Paleozoic Faunal Transition in North-America: An Assemblage-Level Perspective|pages= 1–279|publisher= The University of Chicago}} ''cited on'' {{cite web|website= Fossilworks|author= Shannan Peters|title= Weeksina|url= https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=21037}}</ref>

==References== {{Reflist}}

[[Category:Cambrian trilobites]] [[Category:Ptychopariida genera]] [[Category:Fossils of the United States]] [[Category:Ptychoparioidea]]