A New Cetacean from the Late Eocene La Meseta Formation Seymour Island, Antarctic Peninsula

1989 ◽  
Vol 46 (12) ◽  
pp. 2219-2235 ◽  
Author(s):  
Edward D. Mitchell
Keyword(s):  
New Species ◽  
Antarctic Peninsula ◽  
New Genus ◽  
Late Eocene ◽  
New Genus And Species ◽  
New Family ◽  
Lower Jaw ◽  
La Meseta Formation ◽  
Lobodon Carcinophagus ◽  
Seymour Island

The new genus and species Llanocetus denticrenatus is described based on a cranial endocast and portion of a dentary fragment bearing two teeth from the Eocene La Meseta Formation, Seymour Island, Antarctic Penninsula. Llanocetus new genus is designated the type genus for the new family Llanocetidae. The Llanocetidae is placed within the new infraorder Crenaticeti, co-ordinate with the new Mysticete infraorder Chaeomysticeti. Llanocetus denticrenatus new species shows relationship with both Archaeoceti and Mysticeti. Revision of archaeocete and mysticete classification includes proposal of the new taxa Kekenodontinae, Mammalodontidae, and the new ranks Protocetoidea, Remingtonocetoidea, Basilosauroidea, and Eschrichtioidea. The endocast shows evidence of intracranial retial hypertrophy, taken as evidence of enhanced diving abilities. The large deeply notched teeth are widely spaced on the lower jaw. I hypothesize that filter feeding in whales arose first in species in which teeth with deep notches, forming widey spaced tubercles, comprised part of a straining apparatus analogous to the serrated teeth of the phocid seal Lobodon carcinophagus.

Antarctomithrax thomsoni,a new genus and species of crab (Brachyura; Majidae) from the La Meseta Formation (Eocene) of Seymour Island, Antarctica

1994 ◽  
Vol 68 (1) ◽  
pp. 174-176 ◽  
Author(s):  
Rodney M. Feldmann
Keyword(s):  
Antarctic Peninsula ◽  
Late Cretaceous ◽  
New Genus ◽  
High Energy ◽  
Lower Latitude ◽  
Decapod Crustaceans ◽  
New Genus And Species ◽  
La Meseta Formation ◽  
The Antarctic ◽  
Seymour Island

The james ross basin, situated on the eastern margin of the Antarctic Peninsula, has yielded an extensive fauna of decapod crustaceans spanning Late Cretaceous through Eocene time. To date, 28 species in 22 genera and 18 families have been described (Feldmann, 1992; Feldmann, Tshudy, and Thomson, 1993), making this the most diverse fossil decapod fauna in the Southern Hemisphere. Within the basin, Seymour Island alone contains rocks of the Eocene age La Meseta Formation from which seven species of crabs, one galatheid, and one species of callianassid ghost shrimp have been described (Feldmann and Zinsmeister, 1984; Feldmann and Wilson, 1988; Feldmann, 1992). The fauna of the La Meseta is remarkable also because, although the organisms are preserved in rocks deposited in moderate- to high-energy, shallow-water habitats (Elliot and Trautman, 1982), many of the species represent early occurrences of taxa with living descendants that are characteristic of deeper water, lower latitude habitats (Zinsmeister and Feldmann, 1984).

Short Note: An intriguing penguin bone from the Late Eocene of Seymour Island, Antarctic Peninsula

2008 ◽  
Vol 20 (6) ◽  
pp. 589-590 ◽  
Author(s):  
Piotr Jadwiszczak
Keyword(s):  
Antarctic Peninsula ◽  
Short Note ◽  
Late Eocene ◽  
New Genus And Species ◽  
Type Specimens ◽  
West Antarctic ◽  
Antarctic Convergence ◽  
La Meseta Formation ◽  
The Antarctic ◽  
Seymour Island

Penguins (Aves: Sphenisciformes) are interesting to both neontologists and palaeontologists (e.g. Davis & Renner 2003). The fossil record of these extremely specialized inhabitants of the Southern Hemisphere extends back to the Palaeocene epoch (Slack et al. 2006). Extinct penguins are known from localities within the range of their modern-day relatives (Fordyce & Jones 1990), and the oldest diverse assemblage comes from the Eocene La Meseta Formation of Seymour Island, Antarctic Peninsula, the only such locality south of the Antarctic Convergence (Myrcha et al. 2002, Jadwiszczak 2006a). Several collections amounting to over three thousand bones (mainly isolated skeletal elements) have been acquired since 1901 from that formation, and 15 penguin species have been erected so far (Jadwiszczak 2006a, table 1, Tambussi et al. 2006). Only ten of them (grouped into six genera) appear to be taxonomically distinct, and their type specimens are tarsometatarsi (Simpson 1971, Myrcha et al. 2002, Jadwiszczak 2006a, 2006b, p. 296). Individuals from six species belonging to four genera most probably were not larger than those of Aptenodytes forsteri G.R. Gray, 1844, the heaviest and tallest extant penguin (Jadwiszczak 2001, table 3). Interestingly, representatives of all ten species may have co-existed in the West Antarctic during the Late Eocene epoch, just prior to the final break-up of Gondwana (Jadwiszczak 2006a). Presented here is an intriguing partial tarsometatarsus of a small-sized penguin from the Late Eocene of Antarctic Peninsula, probably representing a new genus and species.

Eocene stelleroids (Echinodermata) at Seymour Island, Antarctic Peninsula

1998 ◽  
Vol 72 (2) ◽  
pp. 339-353 ◽  
Author(s):  
Daniel B. Blake ◽  
Richard B. Aronson
Keyword(s):  
Antarctic Peninsula ◽  
Small Groups ◽  
New Genus ◽  
Late Eocene ◽  
Generic Level ◽  
Basic Composition ◽  
La Meseta Formation ◽  
Jurassic Rocks ◽  
Seymour Island ◽  
Cretaceous Deposits

The new asteroid species Sclerasterias zinsmeisteri (Asteriidae), Paragonaster clarkae, Tesselaster clarki (both Goniasteridae), and the new ophiuroid species Ophiura hendleri (Ophiuridae) are described from the late Eocene La Meseta Formation at Seymour Island, Antarctic Peninsula. The arm tip of an apparently new genus of the Oreasteridae is too incomplete to assign at the generic level. Other La Meseta asteroid species have been described elsewhere. Six of seven recognized stelleroid genera and all represented families survive, and differences between new species and existing congeneric species are subtle. Thus, the La Meseta fauna was similar to living faunas in basic composition.Among La Meseta asteroids, Zoroaster aff. Z. fulgens and Ctenophoraster downeyae are known from numerous specimens; fossils of the other species are comparatively uncommon and given the uncertainties of sampling, further taxa might await discovery at Seymour Island. Although the Paxillosida is known from Jurassic rocks, fasciole-bearing, semi-infaunal genera are first known from Cretaceous deposits, and Astropecten and Astropecten-like Ctenophoraster are first recorded from Cenozoic rocks. Zoroaster and Tesselaster are only known from deep water settings today, although they are found in the La Meseta. Ophiura hendleri, the only ophiuroid recognized to date from the La Meseta, occurs singly, in small groups, and in Paleozoic-type ophiuroid-rich beds.

Xenosellidae, a new family of Janiroidea (Asellota: Isopoda:  Crustacea), for Xenosella coxospinosa gen. nov., sp. nov.,  from the marine bathyal of eastern Australia

Zootaxa ◽  
2005 ◽  
Vol 1085 (1) ◽  
pp. 21 ◽  
Author(s):  
JEAN JUST
Keyword(s):  
New Species ◽  
Body Shape ◽  
New Genus ◽  
New Genus And Species ◽  
South Eastern ◽  
Incertae Sedis ◽  
New Family ◽  
Eastern Australia ◽  
Similar Body ◽  
South Eastern Australia

A new genus and species of janiroidean Asellota, Xenosella coxospinosa, is described from the mid-bathyal slope off the coast of south-eastern Australia. Following a comparison of the new species to several families of broadly similar body shape, with emphasis on monotypic Pleurocopidae, a new family, Xenosellidae, is proposed for the new species. In the course of comparing relevant taxa, the current placements of Prethura Kensley in the Santiidae and Salvatiella Müller in the Munnidae are rejected. The two genera are considered to be incertae sedis within the Asellota superfamily Janiroidea pending further studies.

scholarly journals New Genus and Species of Gall Midges (Diptera, Cecidomyiidae, Porricondylinae, Holoneurini) from the Late Eocene Amber of Olevsk (Zhitomir Region, Ukraine)

2017 ◽  
Vol 51 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Z. A. Fedotova ◽  
E. E. Perkovsky
Keyword(s):  
New Species ◽  
New Genus ◽  
Late Eocene ◽  
Rovno Amber ◽  
New Genus And Species ◽  
Gall Midges ◽  
Two New Species ◽  
First Time ◽  
Eocene Amber

Abstract Gall midges are reported for the first time in Late Eocene Rovno amber from the Olevsk, Zhitomir Region. This is the second amber locality to yield gall midges in the Zhitomir Region, after Gulyanka. Rovnoholoneurus gen. n. and two new species, Rovnoholoneurus davidi sp. n. and R. miyae sp. n. are described. Bryocrypta laqueata Fedotova, 2005 is transferred to the genus Rovnoholoneurus, and Rovnoholoneurus laqueatus (Fedotova, 2005), comb. n. is established. A key to the species of Rovnoholoneurus is provided.

New Monoplacophora (Mollusca) from Late Cambrian and Early Ordovician of Missouri

1986 ◽  
Vol 60 (3) ◽  
pp. 606-626 ◽  
Author(s):  
Bruce L. Stinchcomb
Keyword(s):  
New Species ◽  
New Genus ◽  
New Genera ◽  
New Genus And Species ◽  
Upper Cambrian ◽  
Early Ordovician ◽  
New Family ◽  
Late Cambrian ◽  
Lower Ordovician ◽  
A New Species

Fourteen new species and six new genera of the molluscan class Monoplacophora are described from the Upper Cambrian Potosi and Eminence formations and the Lower Ordovician Gasconade Formation of the Ozark Uplift of Missouri and some new biostratigraphic horizons are introduced. A new superfamily, the Hypseloconellacea nom. trans. Knight, 1956, and a new family, the Shelbyoceridae, are named. The genus Proplina is represented by five new species: P. inflatus, P. suttoni from the Cambrian Potosi Formation, P. arcua from the Cambrian Eminence Formation and P. meramecensis and P. sibeliusi from the Lower Ordovician Gasconade Formation. A new genus and species in the subfamily Proplininae, Ozarkplina meramecensis, is described from the Upper Cambrian Eminence Formation. Four new monoplacophoran genera in the superfamily Hypseloconellacea and their species are described, including: Cambrioconus expansus, Orthoconus striatus, Cornuella parva from the Eminence Formation, and Gasconadeoconus ponderosa, G. waynesvillensis, G. expansus from the Gasconade Formation. A new genus in the new family Shelbyoceridae, Archeoconus missourensis, is described from the Eminence Formation and a new species of Shelbyoceras, S. bigpineyensis, is described from the Gasconade Formation.

The youngest record of fossil land mammals from Antarctica; its significance on the evolution of the terrestrial environment of the Antarctic Peninsula during the late Eocene

1997 ◽  
Vol 71 (2) ◽  
pp. 348-350 ◽  
Author(s):  
S. F. Vizcaino ◽  
M. Bond ◽  
M. A. Reguero ◽  
R. Pascual
Keyword(s):  
Antarctic Peninsula ◽  
Present Note ◽  
Late Eocene ◽  
South American ◽  
Terrestrial Environment ◽  
Shallow Marine ◽  
Early Oligocene ◽  
La Meseta Formation ◽  
The Antarctic ◽  
Seymour Island

The record of fossil land mammals from Antarctica has been restricted previously to the middle levels of the Eocene-?early Oligocene La Meseta Formation in Seymour Island, Antarctic Peninsula. This mostly shallow-marine sequence was divided informally into seven subunits (Tertiary Eocene La Meseta or TELM 1 to 7) by Sadler (1988). Land mammals, representing South American lineages of marsupials, edentates, and ungulates were recovered from TELM 3, 4, and 5 (Marenssi et al., 1994; Vizcaíno et al., 1994). The purpose of the present note is to report the discovery of a well-preserved ungulate tooth from the uppermost level of the La Meseta Formation (TELM 7) and to discuss its paleoenvironmental implications.

scholarly journals The Cephalozygoptera, a new, extinct suborder of Odonata with new taxa from the early Eocene Okanagan Highlands, western North America

Zootaxa ◽  
2021 ◽  
Vol 4934 (1) ◽  
pp. 1-133
Author(s):  
S. BRUCE ARCHIBALD ◽  
ROBERT A. CANNINGS ◽  
ROBERT J. ERICKSON ◽  
SETH M. BYBEE ◽  
ROLF W. MATHEWES
Keyword(s):  
New Species ◽  
New Taxa ◽  
New Genus ◽  
Early Eocene ◽  
Western North America ◽  
New Genus And Species ◽  
Genus Level ◽  
New Family ◽  
Okanagan Highlands ◽  
Head Morphology

We describe the Cephalozygoptera, a new, extinct suborder of Odonata, composed of the families Dysagrionidae and Sieblosiidae, previously assigned to the Zygoptera, and possibly the Whetwhetaksidae n. fam. The Cephalozygoptera is close to the Zygoptera, but differs most notably by distinctive head morphology. It includes 59 to 64 species in at least 19 genera and one genus-level parataxon. One species is known from the Early Cretaceous (Congqingia rhora Zhang), possibly three from the Paleocene, and the rest from the early Eocene through late Miocene. We describe new taxa from the Ypresian Okanagan Highlands of British Columbia, Canada and Washington, United States of America: 16 new species of Dysagrionidae of the existing genus Dysagrion (D. pruettae); the new genera Okanagrion (O. threadgillae, O. hobani, O. beardi, O. lochmum, O. angustum, O. dorrellae, O. liquetoalatum, O. worleyae, all new species); Okanopteryx (O. jeppesenorum, O. fraseri, O. macabeensis, all new species); Stenodiafanus (S. westersidei, new species); the new genus-level parataxon Dysagrionites (D. delinei new species, D. sp. A, D. sp. B, both new); and one new genus and species of the new family Whetwhetaksidae (Whetwhetaksa millerae). 

Systematics and evolution of Paleozoic and Mesozoic damselfly-like Odonatoptera of the ‘protozygopteran’ grade

2012 ◽  
Vol 86 (1) ◽  
pp. 81-104 ◽  
Author(s):  
André Nel ◽  
Günter Bechly ◽  
Jakub Prokop ◽  
Olivier Béthoux ◽  
Gunther Fleck
Keyword(s):  
New Species ◽  
New Genus ◽  
Late Carboniferous ◽  
Late Triassic ◽  
Wing Venation ◽  
Minor Effect ◽  
New Genus And Species ◽  
Triassic Boundary ◽  
Venation Pattern ◽  
New Family

The Paleozoic to Mesozoic grade ‘Protozygoptera’ is revised. It appears to be composed of two main lineages, namely the superfamily Permagrionoidea, and the Archizygoptera. The latter taxon forms a monophyletic group together with Panodonata (=crown-Odonata plus their closest stem-relatives). Therefore, the ‘Protozygoptera’ as previously understood is paraphyletic. Diagnostic characters of the ‘Protozygoptera’, Permagrionoidea, and Archizygoptera are re-evaluated. The Permolestidae is considered as a junior synonym of the Permagrionidae. The following new taxa are described: Permolestes sheimogorai new species, Permolestes soyanaiensis new species, Epilestes angustapterix new species, Solikamptilon pectinatus new species (all in Permagrionidae); Lodeviidae new family (for Lodevia); Luiseiidae new family (including Luiseia breviata new genus and species); Kennedya azari new species, Kennedya pritykinae new species, Kennedya ivensis new species, Progoneura grimaldii new species (all in Kennedyidae); Engellestes chekardensis new genus and species (in Bakteniidae); and Azaroneura permiana new genus and species (in Voltzialestidae). The Kaltanoneuridae and Oboraneuridae are revised. The evolution of protozygopteran Odonatoptera during the transition from the Permian to the Triassic is discussed. The larger taxa of the permagrionoid lineage apparently did not cross through the Permian–Triassic boundary, unlike the more gracile Archizygoptera. This last group shows a remarkable longevity from the late Carboniferous to the Early Cretaceous. It also presents a great taxonomic and morphological stability, with genera ranging from the Permian to the Triassic, and a wing venation pattern nearly unchanged from the late Carboniferous to the Late Triassic. The mass extinction at the end of the Permian period seemingly had a minor effect on these tiny and delicate insects.

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