The plated dinosaur Stegosaurus longispinus Gilmore, 1914 (Dinosauria: Ornithischia; Upper Jurassic, western USA), type species of Alcovasaurus n. gen.

2016 ◽  
Vol 279 (2) ◽  
pp. 185-208 ◽  
Author(s):  
Peter M. Galton ◽  
Kenneth Carpenter
Paleobiology ◽  
1992 ◽  
Vol 18 (1) ◽  
pp. 50-79 ◽  
Author(s):  
Benjamin J. Greenstein

The class Echinoidea apparently originated during the Ordovician Period and diversified slowly through the Paleozoic Era. The clade then mushroomed in diversity beginning in Late Triassic time and continued expanding into the present. Although this evolutionary history is generally accepted, the taphonomic overprint affecting it has not been explored. To gain a more accurate perception of the evolutionary history of the group, I have compared the diversity history of the family Cidaridae (Echinodermata: Echinoidea) with the preservational style of fossil type species using literature-derived data. The Cidaridae apparently originated in Middle Triassic time and diversified slowly through the Neocomian (Early Cretaceous). Diversity was maintained through the remainder of the Cretaceous and Tertiary Periods, reflecting the diversity history of the subclass. Characterization of the preservational style of type fossil material for the family revealed the following breakdown of preservational states: 60% of species were described on the basis of disarticulated skeletal material, primarily spines; 20% based on intact coronas denuded of spines, apical system, Aristotle's lantern and peristomial plates; 10% based on large coronal fragments; and 10% based on other skeletal elements. This distribution may represent the effect of a disarticulation threshold on the condition of echinoid carcasses before final burial and suggests that preservation of intact specimens may be very unlikely. For cidaroids, previous work has suggested that this threshold is likely to be reached after 7 days of decay.Comparison of the diversity history of the Cidaridae with the preservation data reveals that characteristic patterns of taphonomic overprint have affected the group since its origination in Middle Triassic time, and the nature of that overprint has changed over time: the early diversity history of the group is characterized by occurrences of fragmented fossil material, with spines predominant; further radiation of the group in mid-Jurassic time coincided with an increase in modes of preservation, ranging between exceptionally well-preserved material and disarticulated skeletal elements. Finally, type material is more rarely described from younger stratigraphic intervals (Miocene–Pleistocene) and consists predominantly of disarticulated skeletal elements and coronal fragments larger than an interambulacrum in size. Intact, denuded coronas are noticeably lacking.The number of type species of Cidaridae described in each stratigraphic interval has not been consistent during post-Paleozoic time. Middle Triassic, Malm (Upper Jurassic), Senonian (Upper Cretaceous) and Eocene series yielded significantly (α = .05) higher numbers of type specimens per million years, while the Lias (Lower Jurassic), Dogger (Mid-Jurassic), Lower Cretaceous and Paleocene yielded significantly (α = .05) lower numbers of type specimens per million years. This may be the result of a combination of taxonomic, sampling, and geographical biases.


2017 ◽  
pp. 0-0
Author(s):  
Armin Scherzinger ◽  
Günter Schweigert
Keyword(s):  

The new monotypic ammonite genus Xenosphinctes (type species: Xenosphinctes berkai n. sp.) is established. It is recorded from the Upper Jurassic, Early Tithonian, Hybonotum Zone, Riedense Subzone, eigeltingense α horizon from the Talmühle, N of Engen, Baden-Württemberg, SW Germany.


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. 


Zootaxa ◽  
2018 ◽  
Vol 4525 (1) ◽  
pp. 1
Author(s):  
NEO E.B. McADAMS ◽  
JONATHAN M. ADRAIN ◽  
TALIA S. KARIM

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. 


2004 ◽  
Vol 167 (3-4) ◽  
pp. 137-162 ◽  
Author(s):  
Judith Totman Parrish ◽  
Fred Peterson ◽  
Christine E Turner

2021 ◽  
pp. 1-26
Author(s):  
Jonathan M. Adrain ◽  
Talia S. Karim

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


1996 ◽  
Vol 70 (2) ◽  
pp. 335-338 ◽  
Author(s):  
S. Christopher Bennett

One of the rarest pterosaurs from the Upper Jurassic Solnhofen Limestone of southern Germany is Pterodactylus suevicus. Only two specimens are known: the holotype, consisting of a virtually complete skeleton described by Quenstedt (1855); and a second specimen, consisting of only postcranial elements described by Wagner (1858) and lost during World War II (Wellnhofer, 1970). Seeley (1870) noted that P. suevicus differed from P. antiquus, the type species of Pterodactylus, in a number of significant points. Therefore, he placed P. suevicus in a new genus, Cycnorhamphus. Seeley (1870:111) gave the following diagnosis of Cycnorhamphus:“Nares very small, looking upward from a swan-like beak. The middle hole of the skull very large and elongated and lateral. Neck long. Wing-metacarpal long. Four joints in wing-finger. Ilium widening in front. Epipubic bones meeting mesially. The type is Pterodactylus suevicus (Quenstedt).”The character “nares very small” was the result of a misinterpretation of depressions on the premaxillae that probably resulted from crushing, and “middle hole of the skull” referred to the confluent naris and antorbital fenestra, which Seeley apparently considered the antorbital fenestra alone.


Zootaxa ◽  
2009 ◽  
Vol 2160 (1) ◽  
pp. 29-50 ◽  
Author(s):  
JOSTEIN KJÆRANDSEN ◽  
SVANTE MARTINSSON ◽  
KJELL HEDMARK ◽  
NEAL L. EVENHUIS

The five Nordic species of the genus Urytalpa Edwards (Diptera: Keroplatidae) are revised, of which one species, Urytalpa galdes Hedmark & Kjaerandsen, sp. n., is described as new to science based on males collected in northern Sweden. We find that the original type species assignment for Urytalpa (Platyura ochracea Meigen, 1818) is based on a misidentification, and in order to stabilize the nomenclature we therefore select a new type species, Urytalpa dorsalis (Staeger, 1840), sp. restit. A lectotype is designated for Orfelia ochracea (Meigen, 1818), comb. n. = Orfelia unicolor (Staeger, 1840), syn. n. The males of U. atriceps (Edwards, 1913), U. dorsalis, U. macrocera (Edwards, 1913) and U. trivittata (Lundström, 1914), and the females of U. dorsalis, U. macrocera and U. trivittata are described and illustrated based on Nordic material. As the first known Nearctic representative of Urytalpa, U. nigrita (Johannsen, 1910), comb. n., known from western USA (Washington) and Canada, is transferred from Pyrtaula to Urytalpa, illustrated and compared with the closely related U. rhapsodica Chandler, 1995 from central Europe. A key to all known males is provided. The generic limits of Urytalpa as presently understood are vague in relation to related genera and the genus is in need of a revision.


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