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

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.

Zootaxa ◽  
2011 ◽  
Vol 2969 (1) ◽  
pp. 1 ◽  
Author(s):  
NEO E.B. McADAMS ◽  
JONATHAN M. ADRAIN

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. 


2009 ◽  
Vol 46 (12) ◽  
pp. 875-914 ◽  
Author(s):  
Neo E.B. McAdams ◽  
Jonathan M. Adrain

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 .


2001 ◽  
Vol 75 (5) ◽  
pp. 947-971 ◽  
Author(s):  
Jonathan M. Adrain ◽  
Stephen R. Westrop ◽  
Ed Landing ◽  
Richard A. Fortey

Lower Ordovician sections in the type Ibexian area of western Utah contain a considerably more diverse trilobite fauna than has previously been reported. Reinvestigation of these faunas, based on new field sampling, allows a reassessment of the dimeropygid genera Ischyrotoma Raymond, 1925, and Dimeropygiella Ross, 1951. These taxa have been considered synonyms, but parsimony analysis indicates each is a well supported clade, and they are best recognized as sister genera. The number of species known from Ibex has been doubled, from four to eight, and morphological information is now available for most parts of the exoskeleton. New species include Ischyrotoma juabensis (Juab Formation), I. wahwahensis (Wah Wah Formation), Dimeropygiella fillmorensis (Fillmore Formation), and D. mccormicki (Fillmore Formation). The previously named species Dimeropygiella caudanodosa, D. blanda, and D. ovata are fully revised on the basis of abundant new material. Pseudohystricurus is a paraphyletic group, with species distributed as a basal grade of the Ischyrotoma/Dimeropygiella group.


Zootaxa ◽  
2019 ◽  
Vol 4661 (2) ◽  
pp. 201-255
Author(s):  
JONATHAN M. ADRAIN ◽  
TALIA S. KARIM

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.


Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 514
Author(s):  
Zonglei Liang ◽  
Christopher H. Dietrich ◽  
Wu Dai

Xestocephalus Van Duzee is among the most common and widespread genera of Cicadellidae in the temperate and tropical regions of the world. In the present study, 205 specimens of the genus Xestocephalus were collected in Thailand, whereas only a single species of the genus was recorded previously using Malaise trap field sampling, studied by comparative morphology. Seventeen species were recognized, including twelve new species: X. binarius sp. nov., X. chrysanthemum sp. nov., X. cowboyocreus sp. nov., X. densprint sp. nov., X. dimiprocessus sp. nov., X. exproiecturus sp. nov., X. gracilus sp. nov., X. limpidissimus sp. nov., X. malleus sp. nov., X. nonattribus sp. nov., X. recipinams sp. nov., and X. tenusis Liang sp. nov. Four species were recorded in Thailand for the first time: Xestocephalus abyssinicus Heller and Linnavuori, Xestocephalus asper Linnavuori, Xestocephalus ishidae Matsumura, and Xestocephalus toroensis Matsumura. Detailed morphological descriptions of all 17 species are given; photographs of external habitus and male genitalia of the species from Thailand are provided. A checklist of species of the genus is also given, and a key to all Thailand Xestocephalus species is also provided.


2015 ◽  
Vol 46 (1) ◽  
pp. 1-36
Author(s):  
Alexey V. Solovyev

The genus Nirmides Hering, 1931 is revised. Nowadays it includes 17 species, known from Thailand, Vietnam and the Andamans to the Philippines. Eight species are described as new to science: N. siamasp. n. (Thailand), N. ihleisp. n. (Thailand), N. dianasp. n. (Andaman Islands), N. samaressp. n. (Philippines, Samar), N. lourensisp. n. (Philippines, Luzon), N. similissp. n. (Philippines, Mindanao), N. kanlaonensissp. n. (Philippines, Negros), and N. hollowayisp. n. (Borneo). Lectotypes are designated for Susica basalis Walker, 1862 and Nirmides basalis f. fusca Hering, 1931. The taxon Nirma micron van Eecke, 1929 is removed from synonymy with Nirmides basalis (Walker, 1862) and restored to a separate species. A new synonymy is proposed: Nirmides micron (van Eecke, 1929) = Nirmides manwahi Holloway, 1990, syn. n. The homology of the sclerites of the male genitalia is discussed; the musculature of the male genitalia is examined. A key to species is given.


Phytotaxa ◽  
2015 ◽  
Vol 219 (2) ◽  
pp. 174
Author(s):  
Fabiana Firetti Leggieri ◽  
DIEGO DEMARCO ◽  
LÚCIA G. LOHMANN

The Atlantic Forest of Brazil includes one of the highest species diversity and endemism in the planet, representing a priority for biodiversity conservation. A new species of Anemopaegma from the Atlantic Forest of Brazil is here described, illustrated and compared to its closest relatives. Anemopaegma nebulosum Firetti-Leggieri & L.G. Lohmann has been traditionally treated as a morph of Anemopaegma prostratum; however, additional morphological and anatomical studies indicated that A. nebulosum differs significantly from A. prostratum and is best treated as a separate species. More specifically, A. nebulosum is characterized by elliptic and coriaceous leaflets (vs. ovate to orbicular and membranaceous in A. prostratum), smaller leaflet blades (3.6–5.5 x 2.0–3.0 cm vs. 6.7–13.0 x 4.2–8.4 cm in A. prostratum), orbicular prophylls of the axillary buds (vs. no prophylls in A. prostratum), solitary flowers (vs. multi-flowered axillary racemes in A. prostratum) and a gibbous corolla (vs. infundibuliform corollas in A. prostratum). In addition, A. nebulosum differs from A. prostratum anatomically in having thicker leaflet blades composed of two to four layers of palisade parenchyma (vs. one to three layers in A. prostratum), and seven to eight layers in the spongy parenchyma (vs. six to eight layers in A. prostratum). A key for the identification of all species of Anemopaegma from the Atlantic Forest of Brazil is presented.


2007 ◽  
Vol 44 (10) ◽  
pp. 1479-1501 ◽  
Author(s):  
John Pojeta Jr. ◽  
Christopher A Stott

The new Ordovician palaeotaxodont family Nucularcidae and the new genus Nucularca are described. Included in Nucularca are four previously described species that have taxodont dentition: N. cingulata (Ulrich) (the type species), N. pectunculoides (Hall), N. lorrainensis (Foerste), and N. gorensis (Foerste). All four species are of Late Ordovician (Cincinnatian Katian) age and occur in eastern Canada and the northeastern USA. Ctenodonta borealis Foerste is regarded as a subjective synonym of Nucularca lorrainensis. No new species names are proposed. The Nucularcidae includes the genera Nucularca and Sthenodonta Pojeta and Gilbert-Tomlinson (1977). Sthenodonta occurs in central Australia in rocks of Middle Ordovician (Darriwilian) age. The 12 family group names previously proposed for Ordovician palaeotaxodonts having taxodont dentition are reviewed and evaluated in the Appendix.


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