An outer shelf shelly fauna from Cambrian Series 2 (Stage 4) of North Greenland (Laurentia)

2021 ◽  
Vol 95 (S83) ◽  
pp. 1-41
Author(s):  
John S. Peel

AbstractAn assemblage of 50 species of small shelly fossils is described from Cambrian Series 2 (Stage 4) strata in North Greenland, the present day northernmost part of the paleocontinent of Laurentia. The fossils are derived from the basal member of the Aftenstjernesø Formation at Navarana Fjord, northern Lauge Koch Land, a condensed unit that accumulated in a sediment-starved outer ramp setting in the transarctic Franklinian Basin, on the Innuitian margin of Laurentia. Most other small shelly fossil assemblages of similar age and composition from North America are described from the Iapetan margin of Laurentia, from North-East Greenland south to Pennsylvania. Trilobites are uncommon, but include Serrodiscus. The Australian bradoriid Spinospitella is represented by a complete shield. Obolella crassa is the only common brachiopod. Hyoliths, including Cassitella, Conotheca, Neogloborilus, and Triplicatella, are abundant and diverse, but most are represented just by opercula. Sclerites interpreted as stem-group aculiferans (sachitids) are conspicuous, including Qaleruaqia, the oldest described paleoloricate, Ocruranus?, Inughuitoconus n. gen., and Hippopharangites. Helcionelloid mollusks are diverse, but not common; they are associated with numerous specimens of the bivalve Pojetaia runnegari. The fauna compares best with that of the upper Bastion Formation of North-East Greenland, the Forteau Formation of western Newfoundland, and the Browns Pond Formation of New York, but several taxa have a world-wide distribution. Many specimens are encrusted with crystals of authigenic albite. New species: Anabarella? navaranae, Stenotheca? higginsi, Figurina? polaris, Hippopharangites groenlandicus, Inughuitoconus borealis, and Ocruranus? kangerluk.UUID: http://zoobank.org/160a17b1-3166-4fcf-9849-a3cabd1e04a3

1951 ◽  
Vol 29 (1) ◽  
pp. 1-16 ◽  
Author(s):  
L. P. E. Choquette

The systematic position of the genus Rhabdochona Railliet, 1916 and its diagnosis is reviewed. The genus comprising 33 species has a world-wide distribution and has been found, with one exception, in fish. Species from fish in North America are discussed and R. cascadilla Wigdor, 1918 is redescribed; R. laurentiana Lyster, 1940 is considered to be identical with the latter. A new species, R. milleri, is described. A host list and the geographical distribution of the 33 species of Rhabdochona so far recorded are given.


1998 ◽  
Vol 130 (1) ◽  
pp. 27-54 ◽  
Author(s):  
D.J. Larson ◽  
R.W. Wolfe

AbstractThe Agabus semivittatus-group is revised. The group, which is restricted to temperate North America, contains six species: Agabus semivittatus LeConte, which is almost transcontinental; Agabus johannis Fall in peninsular Florida; Agabus astrictovittatus new species along the Atlantic coast from New York to northern Florida and Alabama; Agabus stagninus (Say) along the Atlantic coast from New York to Florida and along the Gulf of Mexico coast to Louisiana; Agabus flavovittatus new species with a wide distribution east of the Great Plains, from southern Ontario to Mississippi and eastern Texas but not along the Atlantic coast; and Agabus texovittatus new species in Texas. Agabus stagninus and A. flavovittatus hybridize in southeastern Pennsylvania. The placement of Agabus texanus Sharp as a junior synonym of A. semivittatus is confirmed. A lectotype is designated for Agabus spilotus LeConte (= A. semivittatus). A neotype is designated for A. stagninus. A key to species is presented and, for each species, the following information is provided: description; illustrations of taxonomically important characters; morphological measurements on selected population samples; notes on relationships, variation, and ecology; and a map of collection localities. A cladistic analysis of the relationships of the group within Agabus indicated that the americanus-, spinipes-, and confusus-groups belong to the same clade as the semivittatus-group and that the seriatus-group is sister to this clade. Within the semivittatus-group, there are three well-defined subgroups as follows: A. semivittatus; A. johannis and A. astrictovittatus; and A. stagninus, A. flavovittatus, and A. texovittatus.


2017 ◽  
Vol 54 (9) ◽  
pp. 961-972 ◽  
Author(s):  
John S. Peel

Bradoriid arthropods are described from the Kap Troedsson and Henson Gletscher formations of North Greenland and the Bastion Formation of North-East Greenland (Cambrian Series 2, Stage 4). Hipponicharion skovstedi n. sp. and Beyrichona avannga n. sp. represent species of genera originally described from Avalonia (New Brunswick) that are characteristic of middle-latitude assemblages in the early Cambrian. They are described for the first time from low-latitude environments in the early Cambrian of Laurentia where they occur together in a middle to upper carbonate ramp succession. Navarana n. gen. is proposed for a rare hipponicharionid currently known only from North Greenland.


2004 ◽  
Vol 41 (11) ◽  
pp. 1273-1283 ◽  
Author(s):  
Christian B Skovsted ◽  
John S Peel ◽  
Christian J Atkins

The cap-shaped Early Cambrian fossil Triplicatella, previously known only from Australia, is reported from the upper Lower Cambrian of North and North-East Greenland, western Newfoundland, and Siberia. The occurrence of Triplicatella in Laurentia strengthens faunal ties between Laurentia and the Australian margin of Gondwana in late Early Cambrian times and supports hypotheses advocating the close proximity for the two palaeocontinents. Two new species, Triplicatella sinuosa n. sp., and T. peltata n. sp. are described, morphological details of which help elucidate the functional morphology and taxonomic affinity of the group. Three opercular types attributable to Triplicatella are left in open taxonomy. The postulated affinity of Triplicatella to hyoliths is confirmed, although the genus can not be placed within either of the two orders of hyoliths currently recognized.


2017 ◽  
Vol 91 (5) ◽  
pp. 871-882 ◽  
Author(s):  
John S. Peel

AbstractThe problematic calcified cnidarian Cambroctoconus is described from the Henson Gletscher Formation (Cambrian Series 2, Stage 4–Series 3, Stage 5) of North Greenland, representing the first record from Laurentia of a genus otherwise recently described from China, Kyrgyzstan, and Korea. Internal molds produced by penetrative phosphatization mirror the pervasive pore system of the calice walls and septa. The pore system is compared to the network of gastrodermal solenia that distributes nutrients between polyps and surrounding stolon tissues in present day octocorals. In conjunction with the octagonal form of the individual coralla and eight-fold symmetry of septa, the pore system promotes assignment of Cambroctoconus to the Octocorallia, a basal clade in cnidarian phylogeny. Octocorals (‘soft corals’) are diverse in present day seas, but have a poor fossil record despite the general development of distinctive calcareous spicules. New taxa: Order Cambroctoconida new; Cambroctoconus koori new species.


2018 ◽  
Vol 93 (1) ◽  
pp. 115-125
Author(s):  
John S. Peel

AbstractPhosphatic sclerites of the problematicTarimspiraYue and Gao, 1992 (Cambrian Series 2) recovered by weak acid maceration of limestones display a unique range of mainly strongly coiled morphologies. They were likely organized into multielement scleritomes, but the nature of these is poorly known; some sclerites may have had a grasping function.Tarimspirasclerites grew by basal accretion in an analogous fashion to younger paraconodonts (Cambrian Series 3–4) but lack a basal cavity. Based on proposed homologies,Tarimspiramay provide an extension of the early vertebrate paraconodont–euconodont clade back into the early Cambrian.Tarimspirais described for the first time from Laurentia (North Greenland), extending its known range from China and Siberia in Cambrian Series 2. In addition to the type species,Tarimspira planaYue and Gao, 1992, the Greenland record ofTarimspiraincludes two morphotypes of a new species,Tarimspira artemi.UUID:http://zoobank.org/c7c536c8-cdaf-49a9-ae1d-77c392f553fc.


1972 ◽  
Vol 41 ◽  
pp. 1-39
Author(s):  
A Weidick

Post-Wisconsinian uplift of West, North and East Greenland has been estimated on the basis of information in current literature and compared to the data collected by the author in central West Greenland. For West and North Greenland the dated uplift allows an estimate to be made of the age of former shore-lines, which in turn have been used to date the stages of the extent of the Inland lce. The results have been compared with published information on the age of glacial stages in East Greenland. The estimated ages of the ice margin stages imply a history of deglaciation in West (and North?) Greenland comparable to that of North America. In both areas the major deglaciation took place after the Younger Dryas and a marked halt took place in Boreal times. It is possibie that the history of East Greenland is more closely related to that of Scandinavia where a widespread deglaciation took place prior to the Younger Dryas. The deglaciation of North Greenland was interrupted by a marked readvance or readvances during the climatic optimum. It is possible that the northward shift of the low pressure centres during this period led to an increased accumulation on the northern part of the Inland lce.


1997 ◽  
Vol 71 (3) ◽  
pp. 360-368
Author(s):  
Richard H. Lindemann ◽  
David A. Melycher

Echinus gyracanthus Eaton, 1832, was the first tentaculitid reported from North America, but the original description and illustration are vague by present-day standards. Study of the type material and topotypes from the Lower Devonian Manlius Limestone in the Town of Schoharie, New York, suggests that Tentaculites gyracanthus (Eaton) is a discrete species, but one with pronounced and remarkable intraspecific variability. Tentaculites simmondsi new species also occurs in the same unit and locality.


Zootaxa ◽  
2009 ◽  
Vol 2306 (1) ◽  
pp. 17-28 ◽  
Author(s):  
ARNE FJELLBERG ◽  
ERNEST C. BERNARD

The eight known species of Agrenia are reviewed and new distributional data are added. Two species groups are suggested for the genus: a bidenticulata-group with a mucronal seta and an agilis-group without a mucronal seta. Four new species of the second group are described from North America: A. falcula, A. parkeri, and A. tarashchukae from forest streams of the Appalachian Mountains in Tennessee, North Carolina, and New York, and A. extrema from glaciers in Washington and Alaska. The head of the maxilla is introduced as a useful character for separation of some species. A key to all species is given.


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