Revision of the Early Ordovician (late Tremadocian; Stairsian) cheirurid trilobite Tesselacauda Ross, with species from the Great Basin, western USA

Zootaxa ◽  
2019 ◽  
Vol 4661 (2) ◽  
pp. 201-255
Author(s):  
JONATHAN M. ADRAIN ◽  
TALIA S. KARIM
Keyword(s):  
New Species ◽  
Great Basin ◽  
Thoracic Segment ◽  
Basic Pattern ◽  
Western Usa ◽  
Early Ordovician ◽  
The Family ◽  
Short Plate

The Stairsian genus Tesselacauda Ross, 1951, has historically included two species, the poorly known type, T. depressa Ross, 1951 (Bearriverops loganensis Zone), and the even less well known T. flabella Kobayashi, 1955 (Bearriverops alsacharovi Zone), which may not belong to the genus. The family assignment of the genus has long been in question, with some workers assigning it to Cheiruridae and some to Pliomeridae. New field collections from western Utah and southeastern Idaho yield abundant material of T. depressa, which facilitates revision on the basis of multiple specimens of most exoskeletal parts. Two additional well known species are proposed, T. morrisoni (Rossaspis leboni Zone), and T. kriegerae (Bearriverops alsacharovi Zone). A third new species, very similar to T. depressa, is described in open nomenclature from the Rossaspis leboni Zone. Knowledge of hypostomes from silicified material helps to clarify the basal morphologies of cheirurid versus pliomerid trilobites. Pliomerids have anteroposteriorly elongate hypostomes with a basic pattern of three pairs of lateral hypostomal spines and a single posteromedian spine. Some or all of the spines are reduced or lost in various taxa. Cheirurids either lack paired spines or have only one or two pairs, and never have a posteromedian spine. Cheirurid hypostomes tend to be much shorter and more subquadrate than pliomerids. Other differences between the families are: a small, triangular or trapezoidal rostral plate in pliomerids versus a wide, short plate in cheirurids; a thoracic segment count commonly of 11–13 in Cheiruridae (fewer in one derived subfamily) versus commonly 15 or more in pliomerids (fewer in two derived subfamilies); thoracic pleurae with subequal bands and a prominent furrow in cheirurids versus a much more inflated and rib-like posterior band, reduced anterior band, and short, anteriorly placed furrow; and pygidia with four or fewer segments in cheirurids versus commonly five in pliomerids (again, fewer in two derived subfamilies). On these and other criteria, Tesselacauda is clearly a cheirurid, assigned for the present to the presumptively basal and possibly paraphyletic Subfamily Pilekiinae.

Two Ordovician asterozoans (Echinodermata) of problematic affinities

2014 ◽  
Vol 88 (6) ◽  
pp. 1163-1173 ◽  
Author(s):  
Daniel B. Blake
Keyword(s):  
New Species ◽  
New Genus ◽  
Early Period ◽  
Early Ordovician ◽  
Class Level ◽  
The Family ◽  
Evolutionary Radiation ◽  
Frame Construction

Phragmactis grayaeSpencer andSwataria derstlerinew genus new species are early (Ordovician) asterozoans (Echinodermata) that comprise the Phragmactinidae. Asterozoans are complexly varied, but as is true for other echinoderms, ambulacral construction is critical to interpretation. Phragmactinids share plesiomorphic aspects of ambulacral form and articulation with basal somasteroids and stenuroids whereas the apomorphic ambulacral expressions of asteroids and ophiuroids are lacking. Phragmactinids, like asteroids and ophiuroids, have only one virgal-series ossicle associated with each ambulacral, unlike the multiple ossicles of somasteroids and stenuroids. Virgal morphology of phragmactinids is reminiscent of expressions in somasteroids and stenuroids. Aspects of phragmactinid mouth frame construction are apomorphic. Morphologies of other ossicular series are similarly varied, and as a result, the family cannot be easily fitted into a recently proposed class-level taxonomy of early asterozoans; it is left in open nomenclature. Phragmactinid morphology does not indicate behavior significantly different from that of other early asterozaons. Asterozoan diversity suggests an early period of rapid evolutionary radiation.

Hesperogaulus, a new genus of mylagaulid rodent (Mammalia) from the Miocene (Barstovian to Hemphillian) of the Great Basin

1999 ◽  
Vol 73 (5) ◽  
pp. 945-951 ◽  
Author(s):  
William W. Korth
Keyword(s):  
New Species ◽  
Great Basin ◽  
Type Species ◽  
New Genus ◽  
Occipital Bone ◽  
Nasal Bones ◽  
The Family ◽  
Two New Species ◽  
Distinct Lineage ◽  
Lower Slope

A new genus of mylagaluid rodent from the Miocene of the Great Basin, Hesperogaulus, is described, and to it two new species, H. gazini and H. wilsoni (type species) are referred. This genus differs from all other genera of later Tertiary mylagaulines in having: large bosses of rugose bone on the anterior end of the nasal bones; lower slope of the occipital bone; and unique separation of the anterior branches of the forked parafossette on the upper premolar.Hepserogaulus n. gen. represents a distinct lineage of mylagaulids that has been separate from other members of the family since the early Barstovian. This genus is geographically limited to the Great Basin. Other later Tertiary genera of mylagaulids show geographic limitations to other parts of the continent as well.

Panisaspis, a new genus of pliomerid trilobites from the Lower Ordovician (Ibexian; Tulean and Blackhillsian) of the Great Basin, western USA

Zootaxa ◽  
2011 ◽  
Vol 2969 (1) ◽  
pp. 1 ◽  
Author(s):  
NEO E.B. McADAMS ◽  
JONATHAN M. ADRAIN
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Great Basin ◽  
Type Species ◽  
New Genus ◽  
Sister Species ◽  
Anterior Border ◽  
Western Usa ◽  
Lower Ordovician

Panisaspis n. gen. is a clade of pliomerid trilobites from the Tulean and Blackhillsian stages (Floian) of the Great Basin.  It includes Protopliomerops? quattuor Hintze, 1953, and ten new species, six of which are formally named: Panisaspis millardensis (type species), P. sevierensis, P. deltaensis, P. rancherensis, P. topscityensis, and P. loganensis.  Four new species are not well enough known for formal naming and are described in open nomenclature.  All species are Tulean in age except for P. millardensis, which is earliest Blackhillsian.  Synapomorphies of Panisaspis include a short, nearly semicircular anterior border; small L1; large genal spines; a rounded, ovoid hypostomal border; elongated third pygidial spines; and a large, triangular terminal piece with distinct pitted impressions.  Phylogenetic analysis indicates that P. millardensis and P. sevierensis are sister taxa, and that P. deltaensis, P. rancherensis, P. topscityensis, P. quattuor, and P. loganensis are successive sister species.  The group may be sister to Ibexaspis Přibyl and Vaněk in Přibyl et al., 1985. 

The pliomerid trilobite Ibexaspis and related new genera, with species from the Early Ordovician (Floian; Tulean, Blackhillsian) of the Great Basin, western USA

Zootaxa ◽  
2018 ◽  
Vol 4525 (1) ◽  
pp. 1
Author(s):  
NEO E.B. McADAMS ◽  
JONATHAN M. ADRAIN ◽  
TALIA S. KARIM
Keyword(s):  
Phylogenetic Analysis ◽  
Great Basin ◽  
Related Species ◽  
Type Species ◽  
New Genera ◽  
Additional Species ◽  
Western Usa ◽  
Early Ordovician ◽  
Laurentian Margin

Field-based revision and phylogenetic analysis demonstrate that the pliomerid trilobite taxon Ibexaspis Přibyl and Vaněk (in Přibyl et al., 1985), previously known from a single formally named species (I. brevis [Young, 1973]), belongs to a complex of 14 mostly newly discovered, related species from the Early Ordovician (Floian; Tulean and Blackhillsian) of the northern Laurentian margin. The species are known from silicified samples recovered from sections in eastern Nevada, western Utah, and southeastern Idaho. The stratigraphically early Tuleaspis n. gen. (type species: T. jeneki n. sp.; Tulean; low Protopliomerella contracta Zone) includes its type and two species described in open nomenclature. Tuleaspis is sister to the remainder of the clade. Ibexaspis now includes three additional species: I. coadyi n. sp. (Blackhillsian; Carolinites nevadensis Zone), I. leuppi n. sp. (Blackhillsian; Presbynileus ibexensis Zone), and I. rupauli n. sp. (Blackhillsian; "Pseudocybele nasuta Zone"). Ibexapsis is sister to a clade of Millardaspis n. gen. + Deltapliomera n. gen. Millardaspis (type species M. milsteadi n. sp.; Tulean; Heckethornia hyndeae Zone) also includes M. knoxi n. sp. (Tulean; Panisaspis sevierensis Zone). Deltapliomera (type species D. humphriesi n. sp.; Blackhillsian, Carolinites nevadensis Zone) also includes D. inglei n. sp. (Tulean; Heckethornia bowiei Zone), D. heimbergi (Tulean; Panisaspis sevierensis Zone), D. eppersoni n. sp. (Blackhillsian; Bathyurina plicolabeona Zone), and a species described in open nomenclature. 

scholarly journals Systematics of the Early Ordovician (late Tremadocian; Stairsian) trilobite Gonioteloides Kobayashi, with species from the Great Basin, western USA

2021 ◽  
pp. 1-26
Author(s):  
Jonathan M. Adrain ◽  
Talia S. Karim
Keyword(s):  
Great Basin ◽  
Type Species ◽  
Distinct Species ◽  
Western Usa ◽  
Early Ordovician ◽  
Phylogenetic Affinity ◽  
Genus One

Abstract The Early Ordovician (late Tremadocian; Stairsian) trilobite Gonioteloides Kobayashi has long been known from a small number of pygidia assigned to a single formally named species, and its affinities have not been assessed. Silicified material from western Utah and southeastern Idaho includes six distinct species assigned to the genus, one of which is the type species. Two others (G. moffitti and G. pankowskii) are new and formally named. An additional three species that are clearly new but known from sparse material are described in open nomenclature. Gonioteloides has a stratigraphic distribution through five consecutive trilobite zones in the mid-Stairsian Stage (upper Tremadocian). Although exoskeletal morphology of three species is almost completely known, the phylogenetic affinity of the taxon remains difficult to determine. It is tentatively assigned to Dimeropygidae Hupé. UUID: http://zoobank.org/23257d6c-262b-4ef5-ae4e-cc431777e67e

Heckethornia, a new genus of dimeropygid trilobites from the Lower Ordovician (Ibexian; Tulean and Blackhillsian) of the Great Basin, western USA

2009 ◽  
Vol 46 (12) ◽  
pp. 875-914 ◽  
Author(s):  
Neo E.B. McAdams ◽  
Jonathan M. Adrain
Keyword(s):  
New Species ◽  
Great Basin ◽  
New Genus ◽  
The Other ◽  
Parsimony Analysis ◽  
Diagnostic Features ◽  
Western Usa ◽  
Lower Ordovician

Heckethornia n. gen. is a morphologically striking clade of dimeropygid trilobites known from the Pogonip Group (Ordovician; Ibexian Series, Tulean and Blackhillsian stages) of western Utah and eastern Nevada. It includes seven species based on silicified material. All occur in the Fillmore Formation of western Utah, and four are also known from the Yellow Hill Limestone of eastern Nevada. Diagnostic features of Heckethornia include a highly vaulted exoskeleton with a tall pygidial “wall” made of fused outer pleurae, three pairs of large glabellar spines, two to three pairs of prominent pygidial spines, a single (or paired) large occipital spine(s), and an arc of tubercles on the librigenal field. Cladistic parsimony analysis suggests that the genus comprises two subclades, one including species with a single median occipital spine, and species with paired occipital spines or tubercles in the other. New species are H. smithi , H. hyndeae , H. numani , H. bowiei , H. morrisseyi , and H. ballionae .

Revision of the Lower Ordovician (lower Floian; Tulean) pliomerid trilobite Protopliomerella, with new species from the Great Basin, western USA

Zootaxa ◽  
2011 ◽  
Vol 3144 (1) ◽  
pp. 1 ◽  
Author(s):  
NEO E. B. MCADAMS ◽  
JONATHAN M. ADRAIN
Keyword(s):  
New Species ◽  
Great Basin ◽  
Field Sampling ◽  
Separate Species ◽  
Western Usa ◽  
Lower Ordovician ◽  
Phylogenetic Status ◽  
Subjective Synonym

New field sampling of classic Ibexian sections in the Great Basin has resulted in the discovery of several new species assignable to the pliomerid trilobite genus Protopliomerella Harrington, 1957. The genus was originally monotypic and based on Protopliomerops contracta Ross, 1951. Protopliomerella pauca Demeter, 1973, was later added, but it is shown herein to be a junior subjective synonym of P. contracta. The material originally assigned to Protopliomerella contracta by Ross belongs to as many as three distinct, stratigraphically separate species. New species include P. stegneri, P. bowlesi, P. kerouaci, P. seegeri, and P. okeeffeae. Two additional new species are not well enough known to name and are reported in open nomenclature. The phylogenetic status of Protopliomerella, as thus conceived, is ambiguous and the taxon may be rendered paraphyletic by the genera Pseudocybele Ross, 1951, and Lemureops McAdams and Adrain, 2009.

Coniosternum masneri sp. nov., a new species of the family Scathophagidae (Diptera) from Canada

2017 ◽  
Vol 186 (1) ◽  
pp. 113-116
Author(s):  
František Šifner
Keyword(s):  
New Species ◽  
Diagnostic Characters ◽  
The Family ◽  
A New Species

Abstract A new Nearctic species of the genus Coniosternum Becker, 1894, C. masneri sp. nov., is described from Canada, and its important diagnostic characters are illustrated.

New and little-known species of the genus Zhengitettix (Orthoptera: Tetrigidae: Scelimeninae) from Southeast Asia

2013 ◽  
Vol 22 (2) ◽  
pp. 204-223
Author(s):  
S.Yu. Storozhenko
Keyword(s):  
New Species ◽  
Southeast Asia ◽  
The Philippines ◽  
Check List ◽  
Key To Species ◽  
The Family

Seven new species of the genus Zhengitettix Liang, 1994 are described: Z. hosticus sp. nov., Z. mucronatus sp. nov. and Z. spinulentus sp. nov. from Vietnam; Z. albitarsus sp. nov. and Z. extraneus sp. nov. from Thailand; Z. palawanensis sp. nov. and Z. taytayensis sp. nov. from the Philippines. Two species, Z. curvispinus Liang, Jiang et Liu, 2007 and Z. obliquespicula Zheng et Jiang, 2005 are firstly recorded from Vietnam. An annotated check-list and key to species of the genus Zhengitettix are given. Position of Zhengitettix within the family Tetrigidae is briefly discussed.

The oldest representatives of the family Coccinellidae (Coleoptera: Polyphaga) from the Lowermost Eocene Oise amber (France)

2012 ◽  
Vol 21 (1) ◽  
pp. 131-144 ◽  
Author(s):  
A.G. Kirejtshuk ◽  
A. Nel
Keyword(s):  
New Species ◽  
Short Review ◽  
The Family ◽  
Two New Species ◽  
Fossil Records ◽  
One New Species ◽  
Eocene Amber

In the paper two new species of the genus Rhyzobius Stephens, 1829 (R. antiquus sp. nov. and R. gratiosus sp. nov.) and one new species of the genus Nephus Mulsant 1846 (N. subcircularis sp. nov. without a certain subgeneric placement) from the Lowermost Eocene amber of Oise are described. A short review of known fossil records of the family Coccinellidae is given.

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