Middle Miocene recovery of Caribbean reef corals: New data from the Tamana Formation, Trinidad

2001 ◽  
Vol 75 (3) ◽  
pp. 513-526 ◽  
Author(s):  
Kenneth G. Johnson
Keyword(s):  
Middle Miocene ◽  
New Records ◽  
Early Miocene ◽  
Early Pleistocene ◽  
Reef Corals ◽  
Rigorous Description ◽  
Caribbean Coral Reef ◽  
The Caribbean ◽  
Stratigraphic Ranges ◽  
Biotic Change

Caribbean coral reef communities were restructured by episodes of accelerated biotic change during the late Oligocene/early Miocene and the late Pliocene/early Pleistocene. However, rigorous description of the effects of rapid biotic change is problematic because preservation and exposure of coral-bearing deposits is not consistent in all stratigraphic intervals. In the Caribbean, early and middle Miocene exposures are more rare than late Miocene and Pliocene exposures. One exception is the late early to early middle Miocene Tamana Formation of Trinidad, and old and new collections from this unit were studied to determine the timing of recovery after the Oligocene/Miocene transition. A total of 41 species of zooxanthellate corals were recovered from the unit, including 21 new records. Within these assemblages, species first occurrences outnumber species last occurrences by a factor of four (31 first occurrences and eight last occurrences). The extension of the stratigraphic ranges of species previously first recorded in Pliocene sediments has reduced an apparent Pliocene pulse of origination, indicating that the Pliocene/Pleistocene transition was largely a result of accelerated extinction against a background of near-constant origination. The fact that few species last occur in the Tamana fauna indicates that the Oligocene/Miocene transition was complete by the end of the early Miocene.

scholarly journals Stratigraphic distributions of genera and species of Neogene to Recent Caribbean reef corals

1994 ◽  
Vol 68 (5) ◽  
pp. 951-977 ◽  
Author(s):  
Ann F. Budd ◽  
Thomas A. Stemann ◽  
Kenneth G. Johnson
Keyword(s):  
Late Miocene ◽  
Species Recognition ◽  
Reef Coral ◽  
Early Pleistocene ◽  
Caribbean Region ◽  
Acropora Palmata ◽  
Free Living ◽  
Reef Corals ◽  
Caribbean Reef ◽  
The Caribbean

To document evolutionary patterns in late Cenozoic Caribbean reef corals, we compiled composite stratigraphic ranges of 49 genera and 175 species using Neogene occurrences in the Cibao Valley sequence of the northern Dominican Republic and faunal lists for 24 Miocene to Recent sites across the Caribbean region. This new compilation benefits in particular from increased sampling at late Miocene to early Pleistocene sites and from increased resolution and greater taxonomic consistency provided by the use of morphometric procedures in species recognition.Preliminary examination and quantitative analysis of origination and extinction patterns suggest that a major episode of turnover took place between 4 and 1 Ma during Plio-Pleistocene time. During the episode, extinctions were approximately simultaneous in species of all reef-building families, except the Mussidae. Most strongly affected were the Pocilloporidae (Stylophora and Pocillopora), Agariciidae (Pavona and Gardineroseris), and free-living members of the Faviidae and Meandrinidae. At the genus level, mono- and paucispecific as well as more speciose genera became regionally extinct. Many of the extinct genera live today in the Indo-Pacific region, and some are important components of modern eastern Pacific reefs. Global extinctions were concentrated in free-living genera. During the turnover episode, no new genera or higher taxa arose. Instead, new species originated within the surviving Caribbean genera at approximately the same time as the extinctions, including many dominant modern Caribbean reef-building corals (e.g., Acropora palmata and the Montastraea annularis complex).Excluding this episode, the taxonomic composition of the Caribbean reef-coral fauna remained relatively unchanged during the Neogene. Minor exceptions include: 1) high originations in the Agariciidae and free-living corals during late Miocene time; and 2) regional or global extinctions of several important Oligocene Caribbean reef builders during early to middle Miocene time.

scholarly journals Neogene amphibians and reptiles (Caudata, Anura, Gekotta, Lacertilia, Testudines) from south of Western Siberia, Russia and Northeastern Kazakhstan

2016 ◽  
Author(s):  
Davit Vasilyan ◽  
Vladimir Zazhigin ◽  
Madelaine Böhme
Keyword(s):  
Northern Hemisphere ◽  
Middle Miocene ◽  
Western Siberia ◽  
Bufo Bufo ◽  
Early Miocene ◽  
Early Pleistocene ◽  
Published Data ◽  
Molecular Clocks ◽  
Western Asia ◽  
Global Cooling

Background. Now-a-day territory of Western Siberia has the poorest diversity of amphibians and reptiles within the Palaearctic Realm, influenced by unfavourable climate. Less is known about the origin and emergence of it. Aside from better-explored European Neogene records of amphibians and reptiles, the Neogene herpetofauna of Western Asia is understudied. The few available studies on amphibian and reptile fossil assemblages need critical reviews and new interpretations considering the latest knowledge of the European record. The comparison with European record will provide data on palaeobiogeographic affiliations of the region as well as origin and emergence of the now-a-day fauna of Western Siberia. Beside these, a study providing overview about the earliest occurences of certain amphibian linages, that can be used for the calibration of the molecular clocks, is missing. Methods and Results. The amphibian and reptile fauna from over 40 Western Siberian, Russia and Northeastern Kazakhian localities ranging from Middle Miocene to Early Pleistocene has been studied. In the study the published data has been considered and critically reviewed and newly interpreted. More then 50 amphibian and reptile taxa has been identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae and Emydidae. Palaeobiogeographic analysis for those group has been done. For 12 localities, palaeoprecipitation values have been estimated using the bioclimatic analysis of herpetofaunal assemblage. Conclusions. The Neogene assemblage of Westren Sibera is dominated by groups (Palaeobatrachidae, Bombina, Hyla, Bufo bufo) with European affinities. A small part of assemblage includes Eastern Palaearctic taxa (e.g. Hynobiidae, Tylototriton, Bufotes viridis, R. arvalis). For several taxa (e.g. Mioproteus, Hyla, Bombina) the Western Siberian records of represent the most east Eurasian records of these groups. The most divers faunas are found in the Middle Miocene, whereas the poorest towards Early Pleistocene. This tendency could be referred to the progressive global cooling of the climate in Northern Hemisphere. Our results showed higher-amplitude changes of precipitation development in Western Siberia from Early Miocene to Pliocene, than earlier assumed.

scholarly journals Neogene amphibians and reptiles (Caudata, Anura, Gekotta, Lacertilia, Testudines) from south of Western Siberia, Russia and Northeastern Kazakhstan

2016 ◽  
Author(s):  
Davit Vasilyan ◽  
Vladimir Zazhigin ◽  
Madelaine Böhme
Keyword(s):  
Northern Hemisphere ◽  
Middle Miocene ◽  
Western Siberia ◽  
Bufo Bufo ◽  
Early Miocene ◽  
Early Pleistocene ◽  
Published Data ◽  
Molecular Clocks ◽  
Western Asia ◽  
Global Cooling

Background. Now-a-day territory of Western Siberia has the poorest diversity of amphibians and reptiles within the Palaearctic Realm, influenced by unfavourable climate. Less is known about the origin and emergence of it. Aside from better-explored European Neogene records of amphibians and reptiles, the Neogene herpetofauna of Western Asia is understudied. The few available studies on amphibian and reptile fossil assemblages need critical reviews and new interpretations considering the latest knowledge of the European record. The comparison with European record will provide data on palaeobiogeographic affiliations of the region as well as origin and emergence of the now-a-day fauna of Western Siberia. Beside these, a study providing overview about the earliest occurences of certain amphibian linages, that can be used for the calibration of the molecular clocks, is missing. Methods and Results. The amphibian and reptile fauna from over 40 Western Siberian, Russia and Northeastern Kazakhian localities ranging from Middle Miocene to Early Pleistocene has been studied. In the study the published data has been considered and critically reviewed and newly interpreted. More then 50 amphibian and reptile taxa has been identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae and Emydidae. Palaeobiogeographic analysis for those group has been done. For 12 localities, palaeoprecipitation values have been estimated using the bioclimatic analysis of herpetofaunal assemblage. Conclusions. The Neogene assemblage of Westren Sibera is dominated by groups (Palaeobatrachidae, Bombina, Hyla, Bufo bufo) with European affinities. A small part of assemblage includes Eastern Palaearctic taxa (e.g. Hynobiidae, Tylototriton, Bufotes viridis, R. arvalis). For several taxa (e.g. Mioproteus, Hyla, Bombina) the Western Siberian records of represent the most east Eurasian records of these groups. The most divers faunas are found in the Middle Miocene, whereas the poorest towards Early Pleistocene. This tendency could be referred to the progressive global cooling of the climate in Northern Hemisphere. Our results showed higher-amplitude changes of precipitation development in Western Siberia from Early Miocene to Pliocene, than earlier assumed.

scholarly journals Rhinocerotidae from the early Miocene of the Negev (Israel) and implications for the dispersal of early Neogene rhinoceroses

2021 ◽  
pp. 1-12
Author(s):  
Luca Pandolfi ◽  
Ran Calvo ◽  
Ari Grossman ◽  
Rivka Rabinovich
Keyword(s):  
Southeast Asia ◽  
South Asian ◽  
North Africa ◽  
Range Expansion ◽  
New Records ◽  
Ct Scanning ◽  
Early Miocene ◽  
Early Neogene ◽  
Postcranial Remains

Abstract A revision of the rhinocerotid material from the Negev (Israel), dating back to the early Miocene (MN3 in the European Mammal Biochronology), highlights the presence of Brachypotherium and a taxon close to Gaindatherium in the Levantine corridor. A juvenile mandible, investigated using CT scanning, displays morphologically distinct characters consistent with Brachypotherium cf. B. snowi rather than with other Eurasian representatives of this genus. Some postcranial remains from the Negev, such as a humerus, display features that distinguish it among Miocene taxa. We attribute these postcrania to cf. Gaindatherium sp., a taxon never recorded outside the Siwaliks until now. This taxon dispersed into the Levantine region during the late early Miocene, following a pattern similar to other South Asian taxa. Brachypotherium cf. B. snowi probably occurred in the Levantine region and then in North Africa during the early Miocene because its remains are known from slightly younger localities such as Moghara (Egypt) and Jebel Zelten (Libya). The occurrence cf. Gaindatherium sp. represents a previously unrecorded range expansion out of Southeast Asia. These new records demonstrate the paleogeographic importance of the Levantine region showcasing the complex role of the Levantine corridor in intercontinental dispersals between Asia and Europe as well as Eurasia and Africa.

Foraminifera Biostratigraphy of Two Wells in Niger Delta

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Dairo VA
Keyword(s):  
Niger Delta ◽  
Middle Miocene ◽  
Early Miocene ◽  
Orbulina Universa ◽  
Exploratory Wells ◽  
Stratigraphic Range

Biostratigraphic studies of foraminifera were carried out on two exploratory wells drilled in the Eastern Niger Delta to establish the age, biozonation and paleoenvironment of the foraminifera present in the strata penetrated by the wells. A total of 80 ditch cutting samples retrieved at 60ft intervals from AX-1 and AX-2 Wells at the depth of 3,600ft to 6,000ft and 4,200ft to 6500ft. respectively were subjected to micropaleontological analysis which involves picking and identification of the foraminifera present. The resulting data were loaded into the Stratabug software and interpreted. The foraminifera recovered and identified from the two wells are made up of both benthic and planktic species. The marker species, whose stratigraphic range are well established were used to describe the biozonation and these includes Heterostegina sp, Catapsydrax stainforthi, Chiloguembelina victoriana, Orbulina universa/suturalis, Praeorbulina sicana,Buliminella subfusiformis, Nonion centrosulcatum, Catapsydrax dissimilis, Globigerinoides bisphericus and Globigerinoides sicanus. Four biozones of foraminifera made up of N8, N7-N8, N6-N7 and N5-N6 were recognised based on the zonation scheme of Grandstein; with their stratigraphic age ranging from early Miocene to middle Miocene. Furthermore, the environment of deposition prevailing in the Formations penetrated by the two wells are predominantly middle neritic with similarity in their ages as observed from the correlation of the biozones from the two wells

Two new species of flattie spiders (Araneae: Selenopidae) and descriptions of undescribed males from the Caribbean

Zootaxa ◽  
2018 ◽  
Vol 4446 (1) ◽  
pp. 125
Author(s):  
SARAH C. CREWS
Keyword(s):  
New Species ◽  
Dominican Republic ◽  
Endemic Species ◽  
New Records ◽  
Caribbean Island ◽  
Two New Species ◽  
The Caribbean

Two new species of Selenops, S. anacaona sp. nov. (♀) and S. caonabo sp. nov. (♀), are described from the Dominican Republic on the Caribbean island of Hispaniola. These two new species increase the number of endemic Selenops on Hispaniola to 13, surpassing Cuba, which currently has 11 endemic species. Additionally, the male of S. pensilis Muma, 1953 from Hispaniola is described, as well as the male of S. petrunkevitchi Alayón, 2003 from Jamaica. Full distribution records are given for the new species and the newly described males, and new records are provided for the following species: S. aequalis Franganillo, 1935, S. bocacandensis Crews, 2011, S. candidus Muma, 1953, S. micropalpus Muma, 1953, S. morro Crews, 2011, S. simius Muma, 1953, S. souliga Crews, 2011, and S. submaculosus Bryant, 1940. 

scholarly journals New records and update on the geographic distribution of the Bonyeared Assfish, Acanthonus armatus Günther, 1878 (Ophidiidae, Neobythitinae), in the Caribbean region

Check List ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 767-772 ◽  
Author(s):  
Andrea Polanco F. ◽  
Luisa F. Dueñas ◽  
Jorge Leon ◽  
Vladimir Puentes
Keyword(s):  
Geographic Distribution ◽  
Current Distribution ◽  
New Records ◽  
Range Extension ◽  
Caribbean Region ◽  
Continental Coast ◽  
Remote Operate Vehicle ◽  
The Caribbean ◽  
First Time

Acanthonus armatus Günther, 1878 is reported for the first time in the southwestern Caribbean region, off Colombia. Remote Operate Vehicle videos and towed camera still photographs captured 13 images of A. armatus between 2215 and 2564 m. These are the first records of the species in the Caribbean continental coast of Colombia, representing a range extension to the southwestern Caribbean region, since previous records are from the northeastern Caribbean. Some photos of the specimens and the current distribution of the species in the Caribbean region are provided and reviewed.

scholarly journals Petrography of the Siwalik sandstones, Amlekhganj-Suparitar area, central Nepal Himalaya

2003 ◽  
Vol 28 ◽  
Author(s):  
Naresh Kazi Tamrakar ◽  
Shuichiro Yokota ◽  
Suresh Das Shrestha
Keyword(s):  
Middle Miocene ◽  
Foreland Basin ◽  
Early Pleistocene ◽  
Nepal Himalaya ◽  
Central Nepal ◽  
Present Study Area ◽  
Mean Grain Size ◽  
Siwalik Group ◽  
Variation Trends ◽  
The Himalaya

Middle Miocene to early Pleistocene sedimentary sequence deposited in the foreland basin of the Himalaya is represented by the Siwalik Group. In the present study area the Siwalik Group extends in a NW-SE direction and well-exposed. Forty­four sandstone samples were studied for texture, fabric and composition in order to assess their petrographic properties and variation trends of these properties in stratigraphic levels. Sandstones were classified into sublitharenite, subarkose, lithic arenite, arkosic arenite and feldspathic graywacke and further thirteen sub-clans. Mean grain size (M) and Trask sorting coefficient (So) increase up-section. Recalculated quartz, matrix, modified maturity index (MMI), total cement (Ct), cement versus matrix index (CMI) and ratio of strong cement over total cement ((Cfc/Cs)/Ct) also increase, whilst packing proximity (PP), packing density (PD) and consolidation factor (Pcc) decrease up-section showing distinct trends, and therefore, these properties are promising in recognizing the older sandstones from the younger ones.

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