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Elisabeth Bay Formation
The Elisabeth Bay Formation, alternatively spelled as Elizabeth Bay Formation, is an Early Miocene ( Aquitanian to Burdigalian, around 21 Ma) geologic formation in the Sperrgebiet, ǁKaras Region of southwestern Namibia, overlying the Blaubok Conglomerate.Dauteuil et al., 2018, p.6 The freshwater green and red siltstones, sandstones, intercalations of conglomerates and claystones of the formation were deposited in a fluvial environment, infilling a paleovalley incised during the Oligocene low sea stand, which backfilled during the Burdigalian marine transgression.Pickford, 2018, p.88 The Elisabeth Bay Formation provides many fossil mammals, snakes and other reptiles. Fossil content The following fossils are reported from the formation: at |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depositional Environment
In geology, depositional environment or sedimentary environment describes the combination of physical, chemical, and biological processes associated with the deposition of a particular type of sediment and, therefore, the rock types that will be formed after lithification, if the sediment is preserved in the rock record. In most cases, the environments associated with particular rock types or associations of rock types can be matched to existing analogues. However, the further back in geological time sediments were deposited, the more likely that direct modern analogues are not available (e.g. banded iron formations). Types of depositional environments Continental * – type of Fluvial deposit. Caused by moving water in a fan shape (Alluvial Fan) and containing mostly impermeable and nonporous sediments well sorted. * . Often in deserts and coastal regions and well sorted, large scale cross-beds * – processes due to moving water, mainly streams. Common sediments are gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ysengrinia
''Ysengrinia'' is an extinct genus of carnivoran in the family Amphicyonidae (beardogs), which lived in Europe, Asia, and North America during the Early Miocene. It was also reported from Egypt and Namibia, but this material has been reassigned to other genera of beardogs ('' Namibiocyon'' and '' Mogharacyon''). Description In North America, ''Ysengrinia'' was part of the faunal turnover ∼23 to 18 Ma, when native larger creodonts and carnivores (including the beardog '' Daphoenus'') were replaced by species emigrating from Eurasia. The genus established a presence across the continent; along with the wide distribution of fossils globally, this suggests ''Ysengrinia'' was flexible in its habits. North American fossil sediments suggest that individuals often lived or found food along rivers and near waterholes. The species may have been dimorphic, with larger males (as in canids and felids) or females (as in hyaenids). Taxonomy ''Ysengrinia'' seems to have been rare t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isohyaenodon
''Isohyaenodon'' ("equal to Hyaenodon") is an extinct polyphyletic genus of hyainailourid hyaenodont mammal from polyphyletic subtribe Isohyaenodontina (of the polyphyletic tribe Hyainailourini within paraphyletic subfamily Hyainailourinae). Remains are known from early to middle Miocene deposits in Kenya, East Africa. Description ''Isohyaenodon'' is distinguished from ''Hyaenodon'' in having more robust molars, lower molars with a subequal paraconid and protoconid, and upper molars with a more well-developed protocone. Classification and phylogeny Taxonomy ''Isohyaenodon'' was considered possibly the same genus as '' Leakitherium'' from the same region by Van Valen (1967), but subsequent studies have rejected this assumption. ''Isohyaenodon pilgrimi'' Savage, 1965 was formerly assigned to this genus, but has been renamed '' Exiguodon pilgrimi''. Phylogeny The phylogenetic relationships of genus ''Isohyaenodon'' are shown in the following cladogram: See also * Mammal class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metapterodon
''Metapterodon'' ("next to '' Pterodon''") is an extinct genus of hyainailourid hyaenodonts of the tribe Metapterodontini withnin paraphyletic subfamily Hyainailourinae, that lived in Africa during the early Oligocene to early Miocene. Fossils of ''Metapterodon'' were recovered from the Egypt, Uganda, Elisabeth Bay Formation in Namibia, and Rusinga Island and Karungu in Kenya. at .org Classification and phylogeny Taxonomy The species ''Metapterodon schlosseri'' and ''Metapterodon markgrafi'' have been reassig ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathyergoides
''Bathyergoides'' is an extinct genus of rodent from Africa thought to be related to the modern blesmols. It is the only member of the family Bathyergoididae. Fossils of ''Bathyergoides neotertiarius'' were recovered from the Early Miocene Elisabeth Bay Formation of Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ....Pickford, 2018, p.88 References Bibliography * Hystricognath rodents Prehistoric rodent genera Miocene rodents Miocene mammals of Africa Fossils of Namibia Fossil taxa described in 1923 Taxa named by Ernst Stromer {{paleo-rodent-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
