scholarly journals A note on the nomenclature of some Upper Jurassic dinoflagellate cyst taxa

1982 ◽  
Vol 1 (1) ◽  
pp. 53-53 ◽  
Author(s):  
Michael J. Fisher ◽  
Leslie A. Riley

Abstract. In 1980, several new species of dinoflagellate cyst taxa were validly published and named from the Kimmeridge Clay of England as part of a larger study on Kimmeridgian-Valanginian dinoflagellate cyst assemblages (Fisher & Riley, 1980); this study was originally presented at the IV International Palynological Conference, Lucknow in 1976–77. This note, necessitated by the long publication delay and numerous printing errors, comprises taxonomic re-allocations, taking account of subsequent studies (Norris, 1978; Stover & Evitt, 1978; Davey, 1979; Riley, 1979) and corrects inadvertent taxonomic errors.

1992 ◽  
Vol 4 (3) ◽  
pp. 267-278 ◽  
Author(s):  
Michael G. Snape

An allochthonous block of the Nordenskjöld Formation from north-west James Ross Island, Antarctic Peninsula has yielded a diverse marine palynoflora. Dinoflagellate cyst assemblages from the 185 m thick sequence are described and compared with similar microfloras previously described from Australia, Papua New Guinea and Madagascar. A mid Tithonian (Late Jurassic) age is suggested for the section. One new genus, Helbydinium gen. nov. and four new species, Helbydinium scabratum sp. nov., Leptodinium acneum sp. nov., Leptodinium posterosulcatum sp. nov. and Rhynchodiniopsis foveata sp. nov. are described.


1988 ◽  
Vol 137 ◽  
pp. 135-159
Author(s):  
M Smelror

The stratigraphic distribution of Upper Bathonian to early Middle Oxfordian dinoflagelIate cysts from localities in Jameson Land and in Milne Land, East Greenland, is evaluated. Using the range of selected species, their earliest appearances andlor extinction, six dinoflagelIate cyst zones and five subzones are proposed for the upper Middle and lower Upper Jurassic succession of central East Greenland. The proposed zonation scheme is correlated with the ammonite zonation of the investigated interval. Two new species, Chytroeisphaeridia grossa sp. nov. and Escharisphaeridia laevigata sp. nov. are formally described.


2021 ◽  
Vol 4 (6) ◽  
Author(s):  
EVGENY V. YAN ◽  
OLESYA D. STRELNIKOVA ◽  
ALEXANDER G. PONOMARENKO

Two species of Jurodidae: Jurodes ignoramus and Jurodes minor are redescribed, new characters presented, and characters from original descriptions are phylogenetically reevaluated, justifying a placement of the family within the suborder Archostemata. The new species Jurodes shef sp. nov. from the Lower Cretaceous locality Khasurty (Berriasian-Barremian, Zakamenskiy district, Buryatia Republic, Russia) is described and 2 new specimens of J. ignoramus Ponomarenko, 1985 and 5 additional specimens of J. minor Ponomarenko, 1990 are recorded. Jurodids from Khasurty are morphologically closer to those from Daohugou locality (Middle–Upper Jurassic, Inner Mongolia, China).


2013 ◽  
Vol 87 (1) ◽  
pp. 105-122 ◽  
Author(s):  
Thomas Saucede ◽  
Alain Bonnot ◽  
Didier Marchand ◽  
Philippe Courville

The discovery of a new species,Cyclolampas altusnew species in the upper Callovian of Burgundy (France) leads to the systematic revision of the rare echinoid genusCyclolampasPomel, 1883. Two morphometric approaches are used jointly to describe and quantify variations in test shape: the analysis of linear measurements and the Elliptic Fourier shape analysis. Both analyses yield congruent results that highlight the amplitude of within-species variations and quantify the part due to allometry. Along with the description ofC. altus, the systematic position of species formerly assigned to the generaPygorhytisPomel, 1883 andCyclolampasis amended. Previously attributed to the genusPygorhytis,Cyclolampas castanea(Desor, 1858) is reassigned to the genusCyclolampason the base of new observations. Conversely, the examination of the Bajocian speciesPygorhytis kiliani(Lambert, 1909) andPygorhytis gillieroniDesor in Desor and de Loriol, 1872, which were previously assigned toCyclolampasnow supports their taxonomic reassignment to the genusPygorhytis. Finally, the two speciesCyclolampas verneuili(Cotteau, 1870) andCyclolampas cotteauiMintz, 1966 (nomen nudum) are considered junior synonyms of the genus type speciesCyclolampas voltzii(Agassiz, 1839). The questioned origin date of the genus, estimated either to the Bajocian or to the Oxfordian, is now clearly established to be upper Callovian. These new results fit well with the overall scheme of atelostomate echinoid evolution and migration to deep-sea environments during the Middle and Upper Jurassic.


1999 ◽  
Vol 18 (2) ◽  
pp. 169-182 ◽  
Author(s):  
Bernard Courtinat

Abstract. The stratigraphic distribution of the Late Callovian to Early Oxfordian dinoflagellate cyst Stephanelytron Sarjeant 1961 emend provides new evidence pertaining to its evolution. Middle and Upper Callovian times favoured the development of speciations to a short-ranging Stephanelytron community with corona(s) in ventral–posterior position (Stephanelytron brontes, S. callovianum, S. ceto and S. tabulophorum) from eurytopic species with antapical coronas (S. caytonense, S. membranoidium, S. redcliffense and S. scarburghense). The former group of species (except S. tabulophorum) may represent an example of peripatric speciation from an unfavourable mutation. The reduced stratigraphic range gives the appearance of an endemic population. The genus Lagenadinium Piel, 1985 is a junior synonym of Stephanelytron Sarjeant, 1961. A new emendation of Stephanelytron, two new combinations (S. callovianum and S. membranoidium) and two new species (?S. brontes and S. ceto) are proposed.


Fossil Record ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Gloria Arratia ◽  
Hans-Peter Schultze ◽  
Helmut Tischlinger

Abstract. A complete morphological description, as preservation permits, is provided for a new Late Jurassic fish species (Tharsis elleri) together with a revision and comparison of some morphological features of Tharsis dubius, one of the most common species from the Solnhofen limestone, southern Germany. An emended diagnosis of the genus Tharsis – now including two species – is presented. The new species is characterized by a combination of morphological characters, such as the presence of a complete sclerotic ring formed by two bones placed anterior and posterior to the eye, a moderately short lower jaw with quadrate-mandibular articulation below the anterior half of the orbit, caudal vertebrae with neural and haemal arches fused to their respective vertebral centrum, and parapophyses fused to their respective centrum. A phylogenetic analysis based on 198 characters and 43 taxa is performed. Following the phylogenetic hypothesis, the sister-group relationship Ascalaboidae plus more advanced teleosts stands above the node of Leptolepis coryphaenoides. Both nodes have strong support among teleosts. The results confirm the inclusion of Ascalabos, Ebertichthys and Tharsis as members of this extinct family. Tharsis elleri n. sp. (LSID urn:lsid:zoobank.org:act:6434E6F5-2DDD-48CF-A2B1-827495FE46E6, date: 13 December 2018) is so far restricted to one Upper Jurassic German locality – Wegscheid Quarry near Schernfeld, Eichstätt – whereas Tharsis dubius is known not only from Wegscheid Quarry, but also from different localities in the Upper Jurassic of Bavaria, Germany, and Cerin in France.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e7803 ◽  
Author(s):  
Daniel J. Chure ◽  
Mark A. Loewen

Allosaurus is one of the best known theropod dinosaurs from the Jurassic and a crucial taxon in phylogenetic analyses. On the basis of an in-depth, firsthand study of the bulk of Allosaurus specimens housed in North American institutions, we describe here a new theropod dinosaur from the Upper Jurassic Morrison Formation of Western North America, Allosaurus jimmadseni sp. nov., based upon a remarkably complete articulated skeleton and skull and a second specimen with an articulated skull and associated skeleton. The present study also assigns several other specimens to this new species, Allosaurus jimmadseni, which is characterized by a number of autapomorphies present on the dermal skull roof and additional characters present in the postcrania. In particular, whereas the ventral margin of the jugal of Allosaurus fragilis has pronounced sigmoidal convexity, the ventral margin is virtually straight in Allosaurus jimmadseni. The paired nasals of Allosaurus jimmadseni possess bilateral, blade-like crests along the lateral margin, forming a pronounced nasolacrimal crest that is absent in Allosaurus fragilis.


2003 ◽  
Vol 77 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Martin J. Head ◽  
Geoffrey Norris

Detailed investigation of the essentially complete uppermost Miocene through Lower Pleistocene sequence in Deep Sea Drilling Project (DSDP) Hole 603C, western North Atlantic, has revealed the presence of the new dinoflagellate cyst speciesLejeunecysta hatterasensis, Lejeunecysta interrupta, Corrudinium devernaliae, andPyxidinopsis vesiculata, as well as the acritarchsLeiosphaeridia rockhallensisHead new species andLeffingwellia costatanew genus and species. Independent magnetobiostratigraphic control of DSDP Hole 603C constrains the ranges of these new species.Lejeunecysta interruptan. sp. appears to range no higher than lowermost Pliocene at 5.2 Ma,Pyxidinopsis vesiculatan. sp. has a range top at about 4.5 Ma in the Lower Pliocene,Corrudinium devernaliaen. sp. has a well-defined range of 4.7–4.1 Ma within the Lower Pliocene, andLeiosphaeridia rockhallensisn. sp. has a similarly well-defined range of 4.4–3.9 Ma within the Lower Pliocene. The presence ofLeiosphaeridia rockhallensisn. sp. in the Ramsholt Member of the Coralline Crag Formation, eastern England, supports an Early Pliocene age for this member.


2014 ◽  
Vol 152 (1) ◽  
pp. 166-175 ◽  
Author(s):  
HAIYAN TONG ◽  
WILAILUCK NAKSRI ◽  
ERIC BUFFETAUT ◽  
VARAVUDH SUTEETHORN ◽  
SURAVECH SUTEETHORN ◽  
...  

AbstractA new genus and new species of primitive eucryptodiran turtle, Phunoichelys thirakhupti gen. et sp. nov., is described on the basis of shell remains from the lower part of the Phu Kradung Formation, at Phu Noi locality, Kalasin Province, NE Thailand. It is assigned to Xinjiangchelyidae on the basis of the marginals covering the lateral end of the costals and the anal scutes invading the hypoplastra. The new taxon is further characterized by a low and rounded carapace without a cervical notch; the whole carapace and plastron covered with a clear ornamentation consisting of tiny irregular vermiculated furrows; a complete neural series that reaches the suprapygal; a very wide and short cervical scute; relatively wide vertebral scutes; and a long first thoracic rib that extends along the full width of the first costal. The sutured plastron/carapace connection and the marginals covering the lateral end of the second to seventh costals suggest that the turtles from Phu Noi may be related to some primitive xinjiangchelyids from the Sichuan Basin. The discovery of a xinjiangchelyid turtle in the lower part of the Phu Kradung Formation supports a Late Jurassic age for that part of the formation.


Sign in / Sign up

Export Citation Format

Share Document