Deviacer pidemarmanii sp. nov. (Polygalaceae) from the Late Eocene–Early Oligocene Badger’s Nose Paleoflora, Modoc County, California

2015 ◽  
Vol 176 (3) ◽  
pp. 259-268 ◽  
Author(s):  
Jeffrey A. Myers ◽  
Diane M. Erwin
Keyword(s):  
Late Eocene ◽  
Early Oligocene

Falcatifolium (Podocarpaceae) macrofossils from paleogene sediments in south-eastern Australia: a reassessment

1998 ◽  
Vol 11 (6) ◽  
pp. 711 ◽  
Author(s):  
Robert S. Hill ◽  
Leonie J. Scriven
Keyword(s):  
Leaf Morphology ◽  
Middle Eocene ◽  
Late Eocene ◽  
South Eastern ◽  
Early Oligocene ◽  
Extant Species ◽  
Eastern Australia ◽  
South Eastern Australia

A re-investigation of macrofossils previously referred to the extantpodocarpaceous genus Falcatifolium Laubenfels shows thatno records can be sustained. Falcatifolium australisD.R.Greenwood from Middle Eocene sediments in Victoria bears littleresemblance to extant species in the genus and is transferred to the newfossil genus Sigmaphyllum R.S.Hill & L.J.Scriven.Specimens from Early Oligocene sediments in Tasmania previously assigned toFalcatifolium are described as a second species ofSigmaphyllum, S. tasmanensisR.S.Hill & L.J.Scriven, and specimens from mid to late Eocene sediments inTasmania previously assigned to Falcatifolium do notbelong to that genus, although their true generic affinities are uncertain.Dispersed cuticle specimens from Late Eocene–Oligocene sediments inSouth Australia referred to Falcatifolium are notreliable records of the genus and require further investigation. However,Dacrycarpus eocenica D.R.Greenwood, from Middle Eocenesediments in Victoria is transferred to Falcatifolium,and is similar to the extant species F. angustumLaubenfels, which has a leaf morphology unusual for the genus.Falcatifolium eocenica (D.R.Greenwood) R.S.Hill & L.J.Scriven is the only reliable record of the genus in the Australian fossilrecord to date.

scholarly journals Angiosperm pollen grains from the Cuayuca Formation (Late Eocene to Early Oligocene), Puebla, Mexico

10.26879/465 ◽  
2015 ◽  
Author(s):  
E Ramírez-Arriaga ◽  
MB Prámparo ◽  
E Martínez-Hernández
Keyword(s):  
Pollen Grains ◽  
Late Eocene ◽  
Early Oligocene ◽  
Angiosperm Pollen

scholarly journals New phiocricetomyine rodents (Hystricognathi) from the Jebel Qatrani Formation, Fayum Depression, Egypt

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12074
Author(s):  
Shorouq F. Al-Ashqar ◽  
Erik R. Seiffert ◽  
Dorien de Vries ◽  
Sanaa El-Sayed ◽  
Mohamed S. Antar ◽  
...  
Keyword(s):  
New World ◽  
New Genus ◽  
Late Eocene ◽  
Type Locality ◽  
New Genus And Species ◽  
Additional Material ◽  
Early Oligocene ◽  
Species Type ◽  
The Rich ◽  
Latest Eocene

Background The rich rodent assemblages from the Eocene–Oligocene deposits of the Jebel Qatrani Formation (Fayum Depression, Egypt) have important implications for our understanding of the origin and paleobiogeography of Hystricognathi, a diverse clade that is now represented by the Afro-Asiatic Hystricidae, New World Caviomorpha, and African Phiomorpha. Methods Here we present previously undescribed material of the enigmatic hystricognath clade Phiocricetomyinae, from two stratigraphic levels in the lower sequence of the Jebel Qatrani Formation—a new genus and species (Qatranimys safroutus) from the latest Eocene Locality 41 (~34 Ma, the oldest and most productive quarry in the formation) and additional material of Talahphiomys lavocati from that species’ type locality, early Oligocene Quarry E (~31–33.2 Ma). Results The multiple specimens of Qatranimys safroutus from L-41 document almost the entire lower and upper dentition, as well as mandibular fragments and the first cranial remains known for a derived phiocricetomyine. Specimens from Quarry E allow us to expand comparisons with specimens from Libya (late Eocene of Dur at-Talah and early Oligocene of Zallah Oasis) that have been placed in T. lavocati, and we show that the Dur at-Talah and Zallah specimens do not pertain to this species. These observations leave the Fayum Quarry E as the only locality where T. lavocati occurs.

scholarly journals Expansion and diversification of high-latitude radiolarian assemblages in the late Eocene linked to a cooling event in the Southwest Pacific

2015 ◽  
Vol 11 (4) ◽  
pp. 2977-3018 ◽  
Author(s):  
K. M. Pascher ◽  
C. J. Hollis ◽  
S. M. Bohaty ◽  
G. Cortese ◽  
R. M. McKay
Keyword(s):  
Oxygen Isotope ◽  
High Latitude ◽  
Large Scale ◽  
Middle Eocene ◽  
Late Eocene ◽  
Climate History ◽  
Southwest Pacific ◽  
Early Oligocene ◽  
Radiolarian Assemblages

Abstract. The Eocene was characterised by "greenhouse" climate conditions that were gradually terminated by a long-term cooling trend through the middle and late Eocene. This long-term trend was determined by several large-scale climate perturbations that culminated in a shift to "ice-house" climates at the Eocene–Oligocene Transition. Geochemical and micropaleontological proxies suggest that tropical-to-subtropical sea-surface temperatures persisted into the late Eocene in the high-latitude Southwest Pacific Ocean. Here, we present radiolarian microfossil assemblage and foraminiferal oxygen and carbon stable isotope data from Deep Sea Drilling Project (DSDP) Sites 277, 280, 281 and 283 from the middle Eocene to early Oligocene (~ 40–33 Ma) to identify oceanographic changes in the Southwest Pacific across this major transition in Earth's climate history. The Middle Eocene Climatic Optimum at ~ 40 Ma is characterised by a negative shift in foraminiferal oxygen isotope values and a radiolarian assemblage consisting of about 5 % of low latitude taxa Amphicraspedum prolixum group and Amphymenium murrayanum. In the early late Eocene at ~ 37 Ma, a positive oxygen isotope shift can be correlated to the Priabonian Oxygen Isotope Maximum (PrOM) event – a short-lived cooling event recognized throughout the Southern Ocean. Radiolarian abundance, diversity, and preservation increase during the middle of this event at Site 277 at the same time as diatoms. The PrOM and latest Eocene radiolarian assemblages are characterised by abundant high-latitude taxa. These high-latitude taxa also increase in abundance during the late Eocene and early Oligocene at DSDP Sites 280, 281 and 283 and are associated with very high diatom abundance. We therefore infer a~northward expansion of high-latitude radiolarian taxa onto the Campbell Plateau towards the end of the late Eocene. In the early Oligocene (~ 33 Ma) there is an overall decrease in radiolarian abundance and diversity at Site 277, and diatoms are absent. These data indicate that, once the Tasman Gateway was fully open in the early Oligocene, a frontal system similar to the present day was established, with nutrient-depleted subantarctic waters bathing the area around DSDP Site 277, resulting in a more oligotrophic siliceous plankton assemblage.

First Paleocene Lepidozona (Mollusca: Polyplacophora: Chitonida) from Ukraine

2021 ◽  
Vol 325 (4) ◽  
pp. 379-383
Author(s):  
B.I. Sirenko
Keyword(s):  
New Species ◽  
Late Eocene ◽  
Early Oligocene ◽  
A New Species

A new species Lepidozona luzanovkensis sp. nov. from Paleocene deposits of Ukraine is described. This find is much earlier than the known finds from the late Eocene or Early Oligocene, which increases the age of the genus Lepidozona Pilsbry, 1892 by several million years.

Data Report: Late Eocene-Early Oligocene Radiolarians, ODP Leg 199 Holes 1218A, 1219A, and 1220A, Central Pacific

2005 ◽  
Author(s):  
S. Funakawa ◽  
H. Nishi ◽  
T.C. Moore ◽  
C.A. Nigrini
Keyword(s):  
Late Eocene ◽  
Central Pacific ◽  
Early Oligocene

Revision of Oligocene ‘Paraphiomys’ and an origin for crown Thryonomyoidea (Rodentia: Hystricognathi: Phiomorpha) near the Oligocene–Miocene boundary in Africa

2019 ◽  
Vol 190 (1) ◽  
pp. 352-371 ◽  
Author(s):  
Hesham M Sallam ◽  
Erik R Seiffert
Keyword(s):  
Type Species ◽  
Close Agreement ◽  
New Genus ◽  
Late Eocene ◽  
Long Period ◽  
Early Oligocene ◽  
South West ◽  
South West Africa ◽  
Divergence Estimates ◽  
First Time

Abstract ‘Paraphiomys’ simonsi is a phiomorph rodent from the early Oligocene of Egypt (~29–30 Mya) that has historically been aligned with much younger (< ~20 Mya) Miocene species of the genera Paraphiomys and Neosciuromys. Here, we use Bayesian tip-dating analysis of a 109-character morphological matrix containing 57 living and extinct ctenohystricans to test these proposed placements for ‘Paraphiomys’ simonsi. Our analyses provide support for the exclusion of ‘Paraphiomys’ simonsi from both Paraphiomys and Neosciuromys and justify the establishment of a new genus (Monamys gen. nov.) for this stem thryonomyoid. These analyses also indicate that the divergence of the extant dassie rat Petromus from the extant cane rat Thryonomys (i.e. origin of crown Thryonomyoidea) occurred ~23.7 Mya, close to the Oligocene–Miocene boundary and in close agreement with recent molecular estimates for this split. Miocene Neosciuromys, Paraulacodus, Protohummus and the type species of Paraphiomys are identified as stem thryonomyids, whereas the Namibian species Apodecter stromeri, Tufamys woodi, ‘Paraphiomys’ australis and ‘Paraphiomys’ roessneri are identified for the first time as stem petromurids, raising the possibility of a long period of endemic petromurid evolution in south-west Africa. Comparison of molecular divergence estimates with our optimal tip-dated topology suggests that stem bathyergoids are most likely to have arisen from late Eocene and early Oligocene ‘phiomyids’.

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