Middle Jurassic (Upper Bathonian and Lower Callovian) jaws of Kosmoceratid ammonites of Central Russia

PalZ ◽  
2021 ◽  
Author(s):  
Vasily V. Mitta ◽  
Aleksandr A. Mironenko
Keyword(s):  
Middle Jurassic ◽  
Central Russia ◽  
Lower Callovian

The Ammonite Zones of the Middle Jurassic Beds of East Greenland

1959 ◽  
Vol 96 (6) ◽  
pp. 505-512 ◽  
Author(s):  
J. H. Callomon
Keyword(s):  
Middle Jurassic ◽  
East Greenland ◽  
Lower Callovian ◽  
Ammonite Zones

AbstractNew discoveries have established the presence of nine ammonite zones in the Middle Jurassic beds of East Greenland. The top two are Lower Callovian; the remaining seven yield ammonites unknown from extra-Boreal provinces and are presumed to range down through the Bathonian, possibly into the Bajocian.

scholarly journals The identity of the Middle Jurassic Ostracoda <i>Fastigatocythere juglandica</i> (Jones) and <i>Lophocythere fulgurata</i> (Jones & Sherborn): a solution to an old enigma

2002 ◽  
Vol 21 (2) ◽  
pp. 155-166 ◽  
Author(s):  
Martin Ware ◽  
Robin C. Whatley
Keyword(s):  
Middle Jurassic ◽  
First Time ◽  
Lower Callovian ◽  
Ostracod Species

Abstract. The Upper Bathonian and Lower Callovian ostracod species Fastigatocythere juglandica (Jones, 1884) is shown to comprise a total of five subspecies. Of these, F. juglandica juglandica, F. juglandica major (Jones &amp; Sherborn, 1888) and F. juglandica postrotunda subsp. nov., described as new herein, are all confined to the Upper Bathonian. Lophocythere fulgurata (Jones &amp; Sherborn, 1888) is demonstrated to be an instar of F. juglandica major. Fastigatocythere juglandica degenerata subsp. nov., described as new herein and F. juglandica rugosa Weinholz comb. nov., both confined to the Lower Callovian, extend the known range of the species into that stage for the first time.

Faunal associations of the Middle Jurassic ammonite genus Macrocephalites in Kachchh, western India

1987 ◽  
Vol 24 (8) ◽  
pp. 1570-1582 ◽  
Author(s):  
Jai Krishna ◽  
G. E. G. Westermann
Keyword(s):  
Middle Jurassic ◽  
Western India ◽  
Nominal Species ◽  
Dimorphic Species ◽  
Lower Callovian

New collections of Macrocephalitinae from the ?Upper Bathonian – Lower Callovian of Kachchh (Cutch olim) make it possible to discern six successive taxonomically distinguishable faunal associations. These are, from above, (6) M. semilaevis association, (5) M. formosus association, (4) M. dimerus association, (3) M. elephantinus association, (2) M. madagascariensis association, (1) M. triangularis association.Of these, Nos. 1, 4, and 6 formed the bases of the M. triangularis, M. dimerus, and M. semilaevis biozones respectively. The majority of the 19 nominal species and 6 genera in the literature on Kachchh may be condensed into only 6 dimorphic species of undivided Macrocephalites.

scholarly journals The age of the Pre-Callovian Jurassic sequence at the southwest of Tatarstan (central Russia, Tarkhanovskaya Pristan’–Dolinovka reference section) and the status of the Upper Bajocian “Garantiana-beds”, previously described from here

2019 ◽  
Vol 27 (6) ◽  
pp. 29-40
Author(s):  
A. P. Ippolitov ◽  
D. B. Gulyaev
Keyword(s):  
Critical Review ◽  
Middle Jurassic ◽  
Basal Part ◽  
Volga River ◽  
Central Russia ◽  
Upper Bajocian ◽  
The Status ◽  
The Republic ◽  
Reference Section ◽  
Jurassic Sequence

In the present paper we describe and discuss belemnite finds from the basal part of the middle Jurassic sequence at the southwest of the Republic of Tatarstan (Tetyushi district). The belemnites were collected from the outcrops located along a shoreline of the Kuybyshevskoye reservoir (Volga river) between the place Tarkhanovskaya pristan and the former village Dolinovka. These belemnites indicate that the basal part of the Jurassic sequence is Early Bathonian (Ishmae Zone) or, less probable, Middle Bathonian in age. Such dating triggers a critical review for the age of the middle Jurassic sequence in the region. In particular, poorly preserved ammonites previously collected from the same outcrops higher in the succession and interpreted as members of the Late Bajocian subfamily Garantianinae, are in fact Late Bathonian Gowericeratinae. Consequently, Beds with Garantiana nominally the most ancient ammonite-based biostratigraphic unit within the whole Jurassic of European Russia, based on this assemblage, is invalid.

scholarly journals Maximum Middle Jurassic transgression in East Greenland: evidence from new ammonite finds, Bjørnedal, Traill Ø

2004 ◽  
Vol 5 ◽  
pp. 31-49 ◽  
Author(s):  
Peter Alsen ◽  
Finn Surlyk
Keyword(s):  
New Species ◽  
Middle Jurassic ◽  
Upper Jurassic ◽  
Middle Part ◽  
The South ◽  
East Greenland ◽  
Lower Upper ◽  
North East ◽  
A New Species ◽  
Lower Callovian

A Middle – lower Upper Jurassic sandstone-dominated succession, more than 550 m thick, with mudstone intercalations in the middle part is exposed in Bjørnedal on Traill Ø, North-East Greenland. A number of ammonite assemblages have been found, mainly in the mudstones. They indicate the presence of the Lower Callovian Cadoceras apertum and C. nordenskjoeldi Chronozones. The mudstones represent northern wedges of the Fossilbjerget Formation hitherto known only from Jameson Land to the south. In Bjørnedal they interfinger with sandstones of the Pelion and Olympen Formations. The presence of the Fossilbjerget Formation in this region indicates complete drowning of the Middle Jurassic sandstone-dominated Pelion Formation during maximum Middle Jurassic transgression. A new species, Kepplerites tenuifasciculatus, is described in the appendix by J.H. Callomon. The holotype and paratype are from Jameson Land, East Greenland, but the species is also found in Bjørnedal, Traill Ø, North-East Greenland.

scholarly journals The ammonite succession in the Middle Jurassic of East Greenland

1993 ◽  
Vol 40 ◽  
pp. 83-113
Author(s):  
John H. Callomon
Keyword(s):  
New Species ◽  
Middle Jurassic ◽  
The Arctic ◽  
European Standard ◽  
East Greenland ◽  
Faunal Assemblages ◽  
Upper Bajocian ◽  
Upper Callovian ◽  
Lower Callovian

The ammonite sequence in the Middle Jurassic of central East Greenland is the most complete and detailed known in the Arctic so far, and has become a standard of reference for the whole of the Bo real Faunal Province. It is made up of some 37 distinguishable assemblages that characterize a time-ordered succession of discrete faunal horizons. This succession has been pieced together from over 80 recorded sections in Jameson Land lying between Scoresby Sund and Kong Oscars Fjord (70-72°N). It forms the biostratigraphic basis for the regional chronostratigraphy. The faunal assemblages are listed and described by reference to published illustrations in the literature. Faunas 1-23 are of pre-Callovian age and have no elements in common with their contemporaries in the classical regions of Europe. They still cannot be correlated with the European standard pre-Callovian chronozonations. Most of them must be of Bathonian age, although the earliest of them could well be, and probably are, even still Upper Bajocian. The Bathonian-Callovian boundary most probably lies some­where in faunas 24-26, which closely resemble those of the keppleri horizon at the base of the Callovian. Faunas 27-35 span the rest of th􀁋 Lower Callovian, while faunas 36 and 37 are the only evidence of Middle and Upper Callovian. The ammonites from Jameson Land previously described by Spath (I 932) are revised and assigned to their correct horizons. Of 11 new species, only one is formally named: Kepp/erites vardekloeftensis sp. nov., of latest Bathonian age.

Sign in / Sign up

Export Citation Format

Share Document