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1.
Zootaxa ; 5336(4): 509-529, 2023 Aug 24.
Article in English | MEDLINE | ID: mdl-38221079

ABSTRACT

Funeralaspis n. gen. (type species F. deathvalleyensis n. sp.) is the oldest known formally named odontopleurine trilobite species, described on the basis of abundant secondarily silicified sclerites of all sclerite types except the rostral plate, from the Dapingian of the Antelope Valley Formation, west flank of the Funeral Range, Death Valley National Park, Inyo County, California. Many Ordovician odontopleurines have been assigned to Diacanthaspis, to the point that it has become something of a taxon of convenience. All of the potential species are listed along with their provenance, preservation, and represented sclerite types. A core group of Diacanthaspis, termed Diacanthaspis (sensu stricto or s.s.) possibly represents a Laurentian clade, consisting of the type species, D. cooperi, and D. lepidus, D. orandensis, D. scitulus, D. secretus, and possibly D. elapsa and D. parvula. This group is characterized by extreme dorsal spinosity, dorsal accessory spines on the base of the genal spine, pygidial spines with lateral fringes of tiny spines, and thoracic and pygidial ring furrows with fringes of tiny spines. Funeralaspis deathvalleyensis has none of the features characteristic of Diacanthaspis and in general scarcely resembles members of this Upper Ordovician group. Remaining species that have been assigned to Diacanthaspis, some of which are very poorly known, should be reclassified as knowledge of Ordovician odontopleurines advances, but for the present are treated as Diacanthaspis (sensu lato or s.l.). A heretofore nearly unknown species described as Ceratocephala maquoketensis from the early Katian of Howard County, Iowa, has not been commented upon in the literature since it was proposed. It is an odontopleurine which in the current state of knowledge should be assigned to the Diacanthaspis (s.l.) group.


Subject(s)
Environment , Fossils , Animals , California
2.
Zootaxa ; 5041(1): 1-73, 2021 Sep 24.
Article in English | MEDLINE | ID: mdl-34811019

ABSTRACT

A diverse mid-Darriwilian trilobite fauna from the Table Cove Formation, western Newfoundland, has long been known on the basis of calcareous specimens from the west coast of the Great Northern Peninsula. Discovery of silicified faunas in localities on the east coast provides additional morphological information for previously known species, and also reveals the presence of multiple new genera and species. Many of these species are important, as they represent some of the earliest Laurentian members of the diversifying Whiterock Fauna, and seem phylogenetically near to the base of their respective clades. The concept of Sphaerexochinae is restricted to the genus Sphaerexochus itself, with the possible inclusion of Newfoundlandops n. gen. (type species N. karimae n. sp.), which shares with Sphaerexochus potential synapomorphies including the structure of the hypostome and the presence of fine granular sculpture on the librigenal border and field. Most of the Early and Middle Ordovician taxa with three pygidial segments previously classified as Sphaerexochinae by many authors are reassigned to Acanthoparyphinae on the basis of multiple putative synapomorphies. Other new cheirurid genera from the Table Cove Formation are the pilekiine Harebayaspis n. gen. (type species H. plurima n. sp.), and the deiphonine Mainbrookia n. gen. (type species M. becki n. sp.). Other species revised or described include the cheirurine Laneites polydorus (Billings, 1865), and the acanthoparyphines Cydonocephalus tiffanyae n. sp., Kawina stougei n. sp., and Kawina? sp.


Subject(s)
Phylogeny , Animals , Canada , Newfoundland and Labrador
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