Rich Brachiopod Fauna Research Articles

UPPER JURASSIC TO LOWERMOST CRETACEOUS MICROFOSSILS FROM THE HĂGHIMAŞ MOUNTAINS (EASTERN CARPATHIANS, ROMANIA)

The limestones of the Upper Jurassic to lowermost Cretaceous from the Hăghimaş Mountains were studied in two sections from the upper part of the Fagu Oltului valley, a tributary of the Olt River. The lower part of the succession is remarkable for the rich brachiopod fauna contained in a red limestone buildup, documented previously as a stromatactis mud-mound. The mound consists of bioclastic wackestones and packstones with numerous brachiopods, crinoids, and sponges. The mud-mound is covered with intraclastic grainstones and fine-grained limestones with pelagic bivalves. The following lithological units pass into shallow water limestone with nerineid gastropods, calcareous algae and foraminifera, in a regressive sequence. The micropaleontological association identified in the Upper Jurassic to lowermost Cretaceous limestones from Fagul Oltului includes calcareous algae, foraminifera, saccocomid crinoid fragments, annelid worm tubes, sponge fragments, rare calpionellids and microorganisms with an uncertain systematic position. The identified microfossils have a wide stratigraphic distribution. The most important stratigraphic landmarks are Trocholina conica (which does not extend younger than Kimmeridgian) and Calpionella alpina (which does not appear before the upper Tithonian). Based on the whole micropaleontological assemblage, the lower part of the succession (the skeletal mud-mound) can be ascribed to the Kimmeridgian – lower-middle Tithonian, and the upper part to the upper Tithonian – Berriasian.

Reef-dwelling brachiopods record paleoecological and paleoenvironmental changes within the Changhsingian (late Permian) platform-margin sponge reef in eastern Sichuan Basin, China.

The eastern Sichuan Basin area (China) is the representative locality for studies of the Late Permian Changhsingian platform to basin transition. However, details of the paleoecology and paleoenvironment of rich brachiopod fauna in this area are still unclear, especially regarding the reef-dwelling brachiopods. The reef-dwelling brachiopod specimens from the Panlongdong platform-margin reefal environment are first described herein. A detailed comparison is presented with the paleoecological features and sedimentological characteristics of the reef-dwelling brachiopods and brachiopods of the reported Zhongliang Hill and Huayingshan intraplatform nonreefal environments in the transitional zone. The reef-dwelling brachiopods are dominated by the spiriferids, such as Martinia and Permophricodothyris, which are mainly found in hypercalcified sponge-calcareous algae binding framestone from the second reef-building process of the Panlongdong reef. The brachiopods in the first and third reef-building processes of the Panlongdong reef often show clear indications of transportation. The comparison of paleoecological and sedimentological evidence indicates that the reef-dwelling brachiopod specimens, which have strong pedicle-attached convex shells and supporting body spines, are commonly preserved in live positions and form a hard-bottom fauna, showing low evenness, and high dominance in both taxonomical and lifestyle diversity. The association among reef-dwelling brachiopod individuals also represents potential biological interactions to prevent the shells from being swept away by constant currents and waves, forming extremely dense concentrations on the sea floor as reef ecosystem engineers. This case study of reef-dwelling brachiopods preserved within the platform-margin reefal environment was critical for filling various gaps in our knowledge of the complexity of the Changhsingian reef-related ecosystem.

Adaptive morphologies of the brachiopod fauna from Danian coral mounds at Faxe, Denmark

Only few of the brachiopod species that lived in the Late Cretaceous Chalk Sea of northern Europe survived the mass extinction at the Cretaceous–Paleogene boundary. However, a rich brachiopod fauna rapidly evolved from the survivors and most of the vacant niches were filled in by the middle Danian when a large cool-water, subphotic coral-bryozoan mound complex was developed at Faxe in the eastern part of the Danish Basin. The brachiopod fauna of the complex comprises 17 species dominated by micromorphic species of similar types as those known from the Upper Cretaceous, Maastrichtian chalk from the same region. All species are found in the coral mound facies and six of the species are restricted to this facies. Large-sized species are rare both in terms of species numbers and abundance. One species is adapted to a life between the branches of the cool-water hexacorals Dendrophyllia candelabrum and Oculina becki. Secondarily free-living species are close to absent. This is in contrast to the Maastrichtian chalk fauna where this group includes 10 species (~24% of the total brachiopod fauna). The otherwise great similarity in morphological adaptations in the brachiopods from the Maastrichtian chalk and the Danian coral mounds is remarkable and somewhat surprising as the latter almost lacks soft substrates. The Danian brachiopod fauna essentially represents a continuation of the Maastrichtian fauna, but in a very different habitat. The similarity between the two faunas is explained by the abundance of small, hard substrates, notably bryozoans in both environments. The brachiopods from Faxe are one of the very few ancient examples of a rich brachiopod fauna from a coral mound environment.

Recent brachiopods collected during the “SEAMOUNT 1” CRUISE off Portugal and the Ibero-Moroccan Gulf (Northeastern Atlantic) in 1987

The Seamount 1 expedition, on board R.V. Noroit in 1987, explored the Lusitanian seamounts off Portugal and the Ibero-Moroccan Gulf of the Northeast Atlantic. A rich brachiopod fauna of about 15 species has been identified in 52 of the 117 stations sampled. The species living around these seamounts are examined, observed using scanning electron microscopy (SEM) to complete their micro-morphological characteristics, and classified in accordance with the Treatise on Invertebrate Paleontology (Brachiopoda Revised, Treatise on Invertebrate Paleontology, Geological Society of America Inc. and University of Kansas, Boulder, Colorado and Lawrence vol. 1 (1997), vols. 2, 3 (2000) and forthcoming volumes). The location of these seamounts, between the Mediterranean and the Caribbean Seas, allows some faunal comparisons to be made. Comparisons are also made with the brachiopod fauna from Seamount 2, which allows taxonomic assessment of the status of one species, Stenosarina crosnieri (COOPER), found in both cruises. Apart from the species characteristics, and the occurrence of early diagenetic transformations of the shells, this paper describes the depth-ranges, the substrate relationships, and highlights the wide colonisation of these seamounts due to the free larval stage of these benthic species.

A Permian phillipsiid trilobite from Peninsular Malaysia

Pygidia of the trilobitePseudophillipsia sp. are reported from the Permian Bera Formation, Pahang, Peninsular Malaysia, in association with a moderately rich brachiopod fauna of early Capitanian (Guadalupian) age. It resembles a slightly younger Capitanian speciesPseudophillipsia acuminata Mansuy, 1912 of northern laos. This find suggests an additional faunal link between Indochina and Peninsular Malaysia (the East Malaya terrane) during Capitanian time.

The Cenozoic Brachiopods of the Carnarvon Basin, Western Australia

The Paleocene-Miocene deposits of the Carnarvon Basin of Western Australia contain a rich fauna of brachiopods, but only two species, Tegulorhynchia boongeroodaensisWestralicrania allani, both from the Paleocene, have previously been described.One new genus, Giraliathyris, and eight new species are described herein. They are Giraliathyris mcnamari, G. kaitrinae, G. jubileensis, Liothyrella longorum, Victorithyris decapello, V. cardabiaensis, V. blakeorum, V. tulkiensis, Diedrothyris cf. johnstonianaParaldingia timi. A Terebratulina species and two species of indeterminate genera are also described. Basiliola (Rhynchonellida) and Cancellothyris (Terebratulida) are recorded for the first time from the upper Paleocene of Australia. These, together with VictorithyrisDiedrothyrisLiothyrella and Paraldingia, represent the oldest records of these genera. It is suggested that their early occurrence, together with those known from the Antarctic Peninsula, indicates a southern origin for this fauna and a high latitude, southern circum-Indo-Atlantic faunal province is proposed. Subsequently the brachiopod fauna spread northwards towards lower latitudes and west to east around southern Australia, before and during the development of the circum-polar current during the Oligocene.

Brachiopods from the Permian–Triassic boundary beds at the Selong Xishan section, Xizang (Tibet), China

The brachiopods from the Waagenites Bed and the upper part of the Coral Bed above and below the Permian–Triassic sequence boundary at the Selong Xishan section of southern Xizang suggest a rich brachiopod fauna existing in Selong, and a rapid invasion of Tethyan brachiopods into the Himalayas at the very end of the Permian. A transgression beginning from the Waagenites Bed and a rapid flooding at the beginning of the Triassic is reflected by changes in composition of the Permian brachiopod assemblages in Selong. However, the dominant forms in the Permian–Triassic sequence boundary beds, including Krotovia, Spiriferella and Neospirifer, extend from the underlying beds of the Selong Group without significant evolutionary change. A brief discussion of each taxon and descriptions of two new species, Stenoscisma selongensis and Martinia attenuatelloides, are presented.

Taxonomy and quantitativebiochronology of Guadalupian brachiopods from the Khuff Formation, Southeastern Oman

The Guadalupian Khuff Formation of the Huqf area (Sultanate of Oman) is composed of marine marls and bioclastic limestones which yield a rich brachiopod fauna associated with conodonts, foraminifers, ostracods, bivalves, gastropods, and cephalopods. The brachiopod fauna of the Khuff Fm. includes Perigeyerella raffaellae nov. sp., Derbyia sp. cf. D. diversa Reed, 1944 , Neochonetes (Sommeriella) arabicus ( Hudson & Sudbury, 1959) , Celebetes manarollai nov. sp., Haydenella sp., Chonetellini? gen. and sp. indet., Dyschrestia rugosa nov. sp., Kozlowskia tescorum ( Hudson & Sudbury, 1959) , Calliprotonia sp., Juresania omanensis Hudson & Sudbury, 1959, Bilotina yanagidai nov. sp., Linoproductus sp. aff. L. kaseti Grant, 1976, Grandaurispina ghabaensis nov. sp., Magniplicatina sp., Cyclacantharia sp., Acritosia sp., Orthotichia sp. cf. O. bistriata Reed, 1944, Cleiothyridina sp. cf. C. seriata Grant, 1976, Pennospiriferinoidea genus and species undetermined, Dielasma sp. A, Dielasma sp. B, Dielasma sp. C, D. sp. aff. D. minor Waagen, 1882 and Hemiptychina sp. This fauna shows strong affinities with that of the Amb Fm. (Salt Range, Pakistan) and that of the Rat Buri Limenstone of southern Thailand. Analysis of the brachiopod data of the Khuff Fm by means of the Unitary Association method (Guex 1991) leads to the construction of a local biochronological sequence of eight faunal associations. Strictly based on a bed rock-controlled sampling, this result provides a firm basis and a first step for future correlations with other Guadalupian brachiopod sequences. It also suggests that species diversity and rates of faunal turnovers are only partly controlled by the vertical succession of depositional environments, which reflects an intra-Khuff asymmetric transgressive-regressive cycle. A full evaluation of the biochronologic component of the Guadalupian brachiopod faunas still requires further tests against other similarly well-documented sequences.

EVIDENCE OF A GUADALUPIAN AGE FOR THE KHUFF FORMATION OF SOUTHEASTERN OMAN: PRELIMINARY REPORT

The Guadalupian succession of the Huqf area (Sultanate of Oman) represents a mega-sequence comprising the fluvial terrigenous Gharif Formation and the overlying marine Khuff Formation. The Khuff Fm. is subdivided into four members and is composed of marls and bioclastic limestones. The Khuff Fm. yields a rich fauna of brachiopods, conodonts, foraminifers, bivalves, gastropods, ostracods and cephalopods. The brachiopod fauna of the Khuff Fm. includes strophomenids, productids, orthids and terebratulids. The associated conodont fauna includes Hindeodus excavatus Behnken, Merrilina sp., M. praedivergens Kozur & Mostler, and Sweetina n. sp. (systematic descriptions of conodonts are given in the Paleontological Appendix). Foraminifers are represented by species of Miliolina and Rotaliina. The Khuff Fm. is given a Wordian age, based on brachiopods and conodonts. The depositional environment of the Khuff Fm. of southeastern Oman corresponds to the outer shelf of a large carbonate platform covering most of the Arabian Platform. The Khuff Fm. is interpreted as a major transgressive-regressive cycle related to differential subsidence.

The age and paleobiogeography of brachiopod fauna discovered in pebbly mudstone at Kilim, Langkawi

A rich brachiopod fauna was recently discovered in the pebbly mudstone overlying sandstone and limestone at Kilim, Langkawi. The fauna comprised Spirelytha buravasi (Hamada), Sulciplica thailandica (Hamada), Bandoproductus monticulus (Waterhouse), Lamniplica cf sap a (Waterhouse), Rhynchopora cf culta Waterhouse, Streptorhynchus sp., Arctitreta sp., Elasmata sp. and Trigonotreta sp. The brachiopod assemblage is very similar to that of Ko Muk in Southern Thailand. The presence of Bandoproductus monticulus (Waterhouse) suggests an Early Permian (Late Asselian to Sakmarian) age for the Kilim pebbly mudstone and its fauna. PaleobiogeographicaUy, the Kilim brachiopod fauna has a very close affinity with many other Early Permian south temperate or peri-Gondwana fauna. The faunal evidence strongly support the idea that the pebbly mudstone in the Singa Formation is of mar ine glacial diamictite.

Early permian (Sakmarian)brachiopods from southeastern Oman

The Lower Permian succession of the Huqf area (Sultanate of Oman) represents the uppermost part of a mega-sequence which includes the Late Carboniferous to? Sakmarian tillites of the Al Khlata Fm. and the overlying transgressive marine Saiwan Fm. of Early Permian age. The Saiwan yields a rich brachiopod fauna associated with bivalves, gastropods, crinoids, conularids, cephalopods and bryozoans. The brachiopod fauna of the Saiwan includes Derbyia haroubi nov. sp., Arctitreta cf. bioni ( Reed), Reedoconcha permixta ( Reed), Neospirifer aff. hardmani ( Foord), Neospirifer sp., Trigonotreta sp., ? Cyrtella aff. nagmargensis ( Bion), Subansiria sp., Punctocyrtella spinosa Plodowski, Punctospirifer sp., Callispirina sp., Fletcherithyris sp., ? Gilledia sp. This brachiopod assemblage indicates a Late Sakmarian age. Application of the Unitary Association method (Guex 1991) to the brachiopod data of the Saiwan leads to establish a local biochronological sequence of three faunal associations.

Les brachiopodes de l'avant-pays ouest-algérien lors de la phase transgressive maximale du Berriasien supérieur; systématique, environnement,paléogéographie

The rich brachiopod fauna of Upper Berriasian age (Boissieri zone) in the Oranian Tellian foreland, is studied forthe first time from the taxonomic point of view. The description of species takes account of both external and internal morphological characters. The microstructural details revealed by the scanning electron microscope show growth rhythms and the diagenetic evolution of the shells. Comparison of the North Africa Berriasian-Valanginian fauna with that of Europe indicates that the palaeogeographic distribution of certain brachiopod species was controlled by latitude and by climate. Finally, the assemblage of palaeoenvironmental and palaeoecological faunal associations is emphasized with brachiopod biocoenoses closely related to the transgressive phase represented by the Boissieri zone. The transgressive phase is part of a 3rd-order depositional sequence (in Vail's sense) dating from the Middle Berriasian to the Late Berriasian on the south-west margin of Tethys.

NEW BRACHIOPOD FAUNAS FROM THE MIDDLE JURASSIC OF ZANSKAR (LADAKH, INDIA)

Several detailed stratigraphical sections have been measured in the Middle Jurassic of the Zan­skar region (Western Himalaya, Ladakh, India). Along six sections in the Laptal Beds and in the Ferruginous Oolite Formation, a rich brachiopod fauna, associated with a few ammonites, has been collected. Most of the brachiopod species are new for the Himalayan region, been so far typical of the Northern Tethys margin. A species, lvanoviella gaetanii sp. n., is erected on material from the Ferruginous Oolite Formation. The age of the lithostratigraphic units yielding fossils is discussed from both brachiopods and ammonites: though little discrepancies are present between the inferred age of brachiopods and ammonites, a Bathonian age for the Laptal Beds and a ?Bathonian, Early Callovian to Oxfordian age for the Ferruginous Oolite Formation is established.

The fauna of the Derfel limestone of the Arenig District of North Wales

The Derfel Limestone, a thin basal member of the Lower Bala of the Arenig-Bala district, north Wales, is exposed only in three localities but has yielded a rich fauna of brachiopods, trilobites, bryozoans and crinoids. A systematic study of the two former phyla shows that the brachiopods are represented by eighteen genera (one, Salopia , is described as new), including nine new species and subspecies, and the trilobites by nine genera. It has previously been believed that the fauna represented a Scoto-Appalachian intrusion into the independent Anglo-Welsh faunal province. But the brachiopods especially are not typical of contemporary Scottish or American sedentary benthos and are better described as a native association dominated by migrants from the east Baltic together with an association of clitambonitids, leptestiinids and productorthinids possibly of Russian origin.

On an Inverted Mass of Upper Cretaceous Strata near Leighton Buzzard, Bedfordshire; and on an Overlap of the Upper Gault in that Neighbourhood

Mr. G. W. Lamplugh and the late Mr. J. F. Walker published a paper in 1903 on a fossiliferous bed at the top of the Lower Greensand, exposed in sand-pits at Shenley Hill, near Leighton Buzzard. The bed in question presented points of considerable lithological interest and was remarkable for its rich brachiopodfauna. Its position above the “silver-sands” of the Lower Greensand and below a capping of dark “shaly clay”, ascribed by those observers to the Lower Gault, led to the conclusion that it belonged to the top part of the Lower Greensand. The discovery of its fossils was considered to throw welcome light on the faunal characters of the latest Lower Cretaceous rocks in England, represented in more southern counties by relatively unfossiliferous sands.