Eocene Species Research Articles

A Paleocene occurrence of cornelian cherries Cornus subg. Cornus in the land-mammal site of Berru (Paris Basin, France)

Cornus subgenus Cornus, also called cornelian cherries, is a relatively ancient clade of dogwoods with a complex biogeographic history. Their fossil record attests to a distribution in North America during the Late Cretaceous and Paleocene, whereas the earliest fossil record in Europe is dated as early as the Eocene. Here, we describe a new occurrence of cornelian cherries based on permineralized endocarps from the late Paleocene (ca. 58 My) land-mammal locality of Berru, in Northwest France. The 48 studied specimens possess characteristic cornelian cherry endocarp morphology with locules associated with a dorsal germination valve, no central vascularization, and the presence of numerous secretory cavities in the endocarp wall. In addition, the presence of (three)-four locules and a large apical depression strongly suggest affinities with the early Eocene species Cornus multilocularis from the London Clay Formation. This new occurrence expands the stratigraphic range of the species by approximately four to six million years and is the first unequivocal evidence of cornelian cherries in Europe during the Paleocene. The biogeographical history of cornelian cherries remains complex to explore because of its ancient distribution in the Cretaceous and a geographically and stratigraphically patchy Cenozoic record.

New Eocene species of the crinoid genera Holopus and Cyathidium (Cyrtocrinida: Holopodidae) from north-eastern Italy.

Holopodidae is one of the three families in the order Cyrtocrinida that have extant representatives. Two genera have been described, Holopus and Cyathidium, both with extant species and fossil representatives dating back to the Cenomanian (Late Cretaceous). Eocene (Lutetian) holopodid material from the Chiampo Valley (north-eastern Italy) has recently been attributed to H. spileccense, the type-stratum and locality of which is the Ypresian of the nearby Spilecco Hill, and to C. gastaldii known from the Miocene of Turin. Here we describe new holopodid material from both Chiampo and Spilecco, comprising cups and numerous brachials. Using qualitative and quantitative characters, the Chiampo holopodids are deemed to be assignable to two new species: Holopus fabianii sp. nov. and Cyathidium chiampoensis sp. nov. The Chiampo material includes the first records of keystone plates and distal brachials for an extinct species of Holopus. New proximal brachials are described for H. spileccense but no keystone plate was found for this species. Access to the holotype of Cyathidium gastaldii has enabled a description of the specimen and a first diagnosis for the species. Formerly described cups, as well as a newly collected one, are attributed to Cyathidium sp. due to the lack of diagnostic characters. The affinities between H. spileccense, H. fabianii sp. nov. and the extant Indo-Pacific H. alidis suggest that these three species might share a common Gondwanan origin.

Hepatics from Rovno amber (Ukraine). 11. Radula oblongifolia and R. tikhomirovae sp. nov.

A study of Rovno amber has revealed two fossil leafy liverwort species of the genus Radula (Radulaceae, Marchantiophyta) that are new to the late Eocene flora of Rovno amber. One of these species, R. oblongifolia, was described previously from Eocene Baltic and Bitterfeld amber, whereas the other species, R. tikhomirovae, is described here as new. Radula tikhomirovae differs from R. oblongifolia and two other Eocene species of that genus, R. sphaerocarpoides and R. baltica, by the presence of microphyllous branches and by the shape of its leaf lobules.

A new Crocodyloidea from the middle Eocene of Zamora (Duero Basin, Spain).

The eusuchian crocodyliforms recorded in the Eocene levels of the Spanish Duero Basin belong to three lineages: Planocraniidae, with the species Duerosuchus piscator; Alligatoroidea, represented by several specimens of the genus Diplocynodon; and Crocodyloidea, which includes several specimens traditionally attributed to Asiatosuchus. The genus Asiatosuchus, established in 1940 based on a middle Eocene species from Mongolia, has subsequently served as a wastebasket taxon for Paleogene remains belonging to several species, not only from Asia but also belonging to the European and North American records. Many of these species are known by highly fragmentary remains, sharing the presence of characters such as a flat and triangular skull, and long symphyses in the lower jaw, recognized as characteristic for the crocodyloids. In addition to isolated cranial remains, among the material traditionally attributed to Asiatosuchus at the Duero Basin stands out a nearly complete skull and a left mandible, from the middle Eocene area of Casaseca de Campeán (Zamora Province). The present study analyses in detail these specimens, previously reported during the 1980s, but analyzed in a very preliminary way. They are included for the first time in a phylogenetic analysis to establish the systematic position of this Spanish form. The results confirm that it corresponds to a new species of basal crocodyloid, defined here as Asiatosuchus oenotriensis sp. nov.

Craniodental ontogenetic variation in the leontiniid coquenia bondi Deraco, Powell, & López, 2008 (Notoungulata, Toxodontia) from the Eocene of Northwestern Argentina

ABSTRACT Craniodental ontogenetic analyses on notoungulates are scarce. Several well-preserved specimens of the Eocene species Coquenia bondi allow for the first ontogenetic study in a Palaeogene leontiniid notoungulate. We studied five almost complete skulls of C. bondi representing three different ontogenetic stages. Cranial ontogeny indicates negative allometry for most of the variables related to the brain and sense organs, with thicker postorbital constriction and braincase breadth in juveniles. The rostrum grows isometrically in length, with positive allometry in height and negative in anterior width. Isometry is recovered for the palatal length and the upper postcanine length, both variables correlated with the longitudinal growth of the splanchnocranium. Other ontogenetic difference is the stouter and sigmoid zygomatic arch in adults, with its posterior root shifted dorsally accompanying the modification of the basicranial angle. Cranial growth of C. bondi is similar to that of Nesodon imbricatus, sharing four coefficients with close values. Molar eruption sequence is anteroposterior, whereas the deciduous premolars are substituted posteroanteriorly. In the juvenile, dentine in M2 is already exposed on the occlusal surface before wear, but the enamel covers the entire crown in m2 of the advanced juvenile.

The first Paleogene record of Hyperisus Mulsant and Rey (Coleoptera: Ptinidae) with description of a new species and an attempt of biogeographic analysis of ptinid assemblage in Baltic amber

ABSTRACT Based on an inclusion in Baltic amber, the first extinct species of the genus Hyperisus Mulsant and Rey, 1863 (Ptinidae: Ernobiinae: Xestobiini), namely H. carstengroehni sp. nov. is described. This new fossil Eocene species differs from extant European congeners in having the dorsal pubescence of two types; the lesser body size; the abdominal ventrite 5 punctate; the dorsal pubescence evenly dense; the antennal club longer than antennomeres 1–8 combined; and in the details of dorsal punctation. Provisional biogeographical affinities of the described Baltic amber Ptinidae (as of July 2023) are briefly analysed. All 20 extant genera known in Baltic amber (100% of analysed assemblage) still inhabit Holarctic of Recent. The ptinid assemblage of Baltic amber is almost twice closer in the composition of genera to the extant fauna of Palearctic or Nearctic than to other regions. Possible explanations are proposed for the abundance of death-watch beetles in Baltic amber.

The galliform birds from the Lower Eocene London Clay of Walton-on-the-Naze (Essex, U.K.): New species suggest faunal connections to Asia

ABSTRACT We report stem group Galliformes from the lower Eocene (Ypresian) London Clay of Walton-on-the-Naze (Essex, U.K.), which are among the oldest known fossils of galliform birds. The specimens are assigned to two new species, ?Paraortygoides argillae, sp. nov. and Waltonortyx bumbanipodiides, gen. et sp. nov. The latter is classified in a new family-level taxon, Waltonortygidae, fam. nov., which differs from other higher-level clades of stem group Galliformes in a proximo-distally narrow caput humeri and a short tuberculum dorsale of the humerus. With regard to these plesiomorphic features and a characteristic morphology of the coracoid, Waltonortyx is similar to early Eocene stem group Galliformes from Mongolia. Wing and pectoral girdle bones of a third, undetermined galliform from Walton-on-the-Naze resemble the Quercymegapodiidae; this fossil also shows a similarity to early Eocene galliforms from Mongolia. The affinities of “Paraortygoides” radagasti Dyke and Gulas, 2002, the only previously described putative galliform from Walton-on-the-Naze, are uncertain and neither its classification in the Galliformes nor its assignment to the taxon Paraortygoides are unequivocally established. For the first time we subjected a larger taxonomic sample of early Paleogene Galliformes to a formal analysis, and even though the resulting phylogenies were poorly resolved, they supported paraphyly of the Quercymegapodiidae, with the Early Miocene taxon Ameripodius being more closely related to the crown group than the late Eocene species of Quercymegapodius. Waltonortyx bumbanipodiides was recovered as the sister taxon of the Mongolian Bumbanipodius transitoria, which indicates early Paleogene dispersal events across the Turgai Strait.

Toward an understanding of gleicheniaceous fern evolution; organismal concept for an Eocene species from western North America

Anatomically preserved fossil gleicheniaceous fern remains in carbonate marine concretions from Vancouver Island, British Columbia, Canada support the development of a whole plant concept for an Eocene species of Gleichenia, and provide data to develop the first organismal concept for an extinct species of Gleichenia from the Cenozoic fossil record. New information for completing the plant reconstruction includes anatomically preserved pinnule fragments with attached radial exindusinate sori of six to seven annulate sporangia containing trilete spores. While the overall pattern of evolution within Gleicheniaceae remains incompletely understood because well-documented fossils from pre-Cretaceous deposits are inconsistently preserved, this organismal plant concept strengthens evidence that all diagnostic features of the family Gleicheniaceae were present, and that essentially modern species were well-established and diversifying during the Cretaceous and Paleogene.

New data on Biphyllidae (Coleoptera: Cucujiformia: Cleroidea) from Baltic amber: more diverse assemblage than previously assumed and its climatic interpretation

ABSTRACT Two new extinct species of false skin beetles (Biphyllidae) are described and illustrated based on inclusions in Baltic amber: Biphyllus lar sp. nov. and Coelodiplus uuu-impressa gen. et sp. nov. The new Eocene fossils are compared with the related extant and extinct representatives of the family. A new monotypic genus is erected for one fossil; another Eocene species is classified within the extant genus Biphyllus Dejean, 1821. The holotype of Diplocoelus probiphyllus Vitali, 2010 (Baltic amber) is re-examined and its diagnosis is emended. The present paper brings the total number of described biphyllid species from European succinite to three. A key to all documented fossil species of the family is provided. Several aspects of insect use as paleoenvironment and climate proxies are briefly discussed. On the basis of the revealed biphyllid palaeofauna and analysis of the climatic extremes of the modern distribution of the family in the Northern Hemisphere, the lowest possible annual temperature in the area of amberiferous forests of Eocene Northern Europe is hypothesised.

Morphometrics and machine learning discrimination of the middle Eocene radiolarian species Podocyrtis chalara, Podocyrtis goetheana and their morphological intermediates

We present various approaches to distinguish the middle Eocene species Podocyrtis chalara and Podocyrtis goetheana, which are end members of a trajectory of phenotypic change, and their intermediate morphogroups. We constructed a set of thirteen traditional morphological variables to classify the entire morphological variability encompassed by the two morphospecies and their intermediates Podocyrtis sp. cf. P. chalara and Podocyrtis sp. cf. P. goetheana. We used two methods of classification, namely Linear Discriminant Analysis (LDA) and machine learning using artificial neural networks. LDA performed on the morphometric data reveals a good discrimination for P. chalara, P. goetheana and Podocyrtis sp. cf. P. goetheana, but not for Podocyrtis sp. cf. P. chalara. We used three approaches of machine learning based on different neural networks: a Convolutional Neural Network (CNN) and two Spiking Neural Networks (SNNs). Each of these neural networks was trained based on classified images of the two morphospecies and their morphological intermediates, thus constituting a different set of input data than the morphometric dataset for LDA. The neural network approaches identified the same three morphospecies recognized by LDA from a dataset of traditional measurements, i.e. P. chalara, P. goetheana and Podocyrtis sp. cf. P. goetheana, with up to 92% accuracy. Our results highlight the great potential and promising perspectives of machine learning and neural networks in the application of image-based object recognition for morphological classification, which may also contribute to more objective taxonomic decisions.

Turbiosphaera archangelskyi sp. nov. and a morphological complex from the late Middle to Late Eocene of southern high latitudes: Biostratigraphic, palaeoenvironmental and palaeoceanographic implications

We record a morphological complex of species of the dinoflagellate-cyst genus Turbiosphaera from the uppermost Río Turbio Formation, considered to be of late Priabonian age, and from equivalent units of the Austral-Magallanes Basin, southern Argentina and southern Chile. Previously, specimens now assigned to Turbiosphaera archangelskyi sp. nov and Turbiosphaera sarrisii were assigned to the cosmopolitan latest Maastrichtian to Middle Eocene species Turbiosphaera filosa. We now identify three species in our Turbiosphaera archangelskyi species complex, which excludes Turbiosphaera filosa. At one end of the complex is Turbiosphaera sarrisii with incipient processes, and at the other end, with well-developed individual processes, is Turbiosphaera sagena. The new species, Turbiosphaera archangelskyi, represents the intermediate stage and is the most abundant form. These three species have only been recorded together in the Austral-Magallanes Basin; their earliest occurrences are slightly asynchronous: Turbiosphaera sarrisii and Turbiosphaera archangelskyi have earliest occurrences in the late Bartonian, but that of Turbiosphaera sarrisii is slightly older. The earliest occurrence of Turbiosphaera sagena is recorded in the middle Priabonian. Our results highlight the biostratigraphic value of these species and their limited palaeogeographical distribution. The morphological variability exhibited by the Turbiosphaera archangelskyi species complex in the latest Eocene may be environmentally influenced, perhaps reflecting the deepening of the Drake Passage and the consequent influx of low-salinity water from the shelf and nearshore regions of the southeastern Pacific onto the Patagonian Shelf.

First Record of the Genus Cartorhynchites Voss, 1958 (Coleoptera: Rhynchitidae) from Eocene Baltic Amber with a List of Fossil Tooth-Nosed Snout Weevils.

A new species of the genus Cartorhynchites (Rhynchitini, Rhynchitina) is described from Baltic amber. Cartorhynchites groehni Legalov, Bukejs et Alekseev sp. n. differs from C. struvei Zherikhin, 1992 from the Miocene of Germany in its smaller body size (2.6 mm), strongly convex eyes, narrower pronotum and wide elytra, and dark brown legs. A new species is studied and illustrated in detail using X-ray micro-computed tomography (μCT). It is the earliest fossil record of subtribe Rhynchitina. A list of fossil Rhynchitidae was compiled. A key to species of Rhynchitidae in Baltic amber was given. Fossil finds of the family Rhynchitidae were discussed. The assumption was made that the Recent distribution range of the genus Cartorhynchites is within the range of its host plant of the genus Symplocos. Probably, a new Eocene species developed on Symplocos kowalewskii, and the Oligocene C. struvei was associated with Symplocos myosotis (Unger).

New records of the subgenus Atomaria (Anchicera) Thomson, 1863 from European amber with description of the new species

ABSTRACT One new extinct species of the genus Atomaria Stephens, 1829 is described and illustrated: A. (Anchicera) telnovi sp. nov. from Rovno amber. It is the sixth species of the subgenus Anchicera in Eocene amber; two-thirds of all species and two-thirds of all reported Eocene amber silken fungus beetle specimens belong to this subgenus. The reasons for the relative abundance of Anchicera in the Eocene fossil resins are discussed. A key to extinct Eocene species of Atomaria is provided.

Shell characterization of the youngest valid species of the European Eocene genus Neochelys (Pleurodira, Podocnemididae): The Spanish Bartonian Neochelys salmanticensis

The freshwater pleurodiran turtle Neochelys is the best-represented member of Podocnemididae in the European record, being known by eight Eocene species. The youngest of them is the Bartonian (middle Eocene) Neochelys salmanticensis, from the Duero Basin (Salamanca Province, Central Spain). It corresponds to the largest representative known for this genus, its shell reaching 50 cm in length. Despite this form was defined several decades ago, the information currently available on it is very limited, being restricted to shell remains of less than 10 individuals. In fact, this species lacks a valid diagnosis, considering the current knowledge about the genus. Numerous remains (i.e., more than 1,200) of the shell of this Spanish species are identified. Its detailed study is presented here, so that the anatomy of its shell is characterized in detail. In addition, several aspects related to its intraspecific variability are analyzed, relative to the individual, ontogenetic, and sexual variability. In this way, the shell of N. salmanticensis can be characterized with greater precision than that of any other species of the genus.

PALEONTOLOGY, STRATIGRAPHY AND PALEOGEOGRAPHY OF THE TETHYAN MAASTRICHTIAN-NEOGENE ROTALIID BENTHIC FORAMINIFERAL MEMBERS OF THE GENUS PARAROTALIA

The modern taxonomical consideration is used for most diagnostic sixteen Maastrichtian-Neogene Rotaliid benthic foraminiferal species of the genus Pararotalia Le Calvez which has wide geographic distribution in many Tethyan sites: USA, Northern Tethys (England, France, Belgium, Holland, Germany, Italy, Poland, Slovenia, Romania) and Southern Tethys (Libya, Egypt, Tanzania, UAE, Pakistan, India). The Maastrichtian-Paleocene species is P. tuberculifera (Reuss). The Paleocene species is P. macneili Loeblich and Tappan. The Paleocene-Eocene species is P. ishamae Loeblich and Tappan. The Eocene species are: P. audouini (d’Orbigny), P. clavezae Loeblich & Tappan, P. inermis (Terquem), P. khirthari Haque, and P. pakistanica Anan. The Eocene-Oligocene species is P. spinigera (Le Calcez). The Oligocene species are: P. byramensis (Cushman), P. curryi Loeblich & Tappan, P. parva (Cushman) and P. subinermis Bhatia. The Neogene species are: Pararotalia aculeata (d’Orbigny), P. armata (d’Orbigny) and P. loeblichi Anan. One species is believed to be new: Pararotalia loeblichi Anan, n. sp. Eight species of them were recorded from USA (about 50%), 6 from Romania (about 37.5%), 5 from each of France, Egypt, UAE and Pakistan (about 31.5%), 3 from Poland (about 19%), 2 from Belgium, Italy and Slovenia (about 12.5%), 1 species from each of England, Libya and India (about 6%). The petaloid test and keeled peripheral margin are mostly represented warm water environment.

Review and revision of the Olivoidea (Neogastropoda) from the Paleocene and Eocene of the U.S. Gulf Coastal Plain

AbstractNumerous species of “oliviform” gastropods have been recognized in the Paleogene of the U.S. Gulf Coastal Plain, many of which have previously been allied to the “Bullia group” in the family Nassariidae, and placed in a variety of poorly defined genera. We review these species, revise their generic and familial placement, and present a phylogenetic analysis. Of 19 species considered valid, all are assigned to Olivoidea, six to Olividae—one to Oliva, five to Agaronia—and the rest to Ancillariidae. The highly variable species Ancillaria altile Conrad is referred in the genus Ancillopsis and appears to have evolved anagenetically over an interval of perhaps 20 million years. Ancillaria tenera Conrad and Ancillaria scamba Conrad are placed in the new genus Palmoliva. Monoptygma Lea is demonstrated to belong to Ancillariidae, and to contain only a single species. Specimens assigned to Lisbonia expansa Palmer are split into adults assigned to Ancillopsis altilis and juveniles (together with several other species) in the long-lived species Anbullina elliptica (Whitfield). Coastal Plain ancillariids may have evolved from one or more species of the Cretaceous–Paleocene genus Eoancilla. We agree with previous authors who have suggested that the late Eocene species Oliva mississippiensis Conrad is the earliest known representative of this genus and the subfamily Oliviinae, perhaps derived from a species of Agaronia. The oldest Agaronia is lower Eocene (Ypresian).UUID: http://zoobank.org/b7d9f79b-c68b-4385-aba3-bb07c6d6dc87

An Eocene fossil plutoniumid centipede: a new species of Theatops from Baltic Amber (Chilopoda: Scolopendromorpha)

Four specimens of the same species of scolopendromorph centipede from Eocene Baltic amber provide the first fossil occurrence of the family Plutoniumidae, a clade represented by seven extant species. The fossil material, documented by light microscopy and computed microtomography, is assigned to the genus Theatops Newport, 1844, which currently has a disjunct distribution in temperate North America, the Mediterranean region, and central China. The Eocene species is diagnostically distinct from extant congeners and is formally described as Theatops groehni sp. nov. Phylogenetic analysis of combined morphological and molecular data for three loci finds T. groehni to be nested within crown-group Plutoniumidae. The discovery of T. groehni constrains the minimal divergence date for crown-group Plutoniumidae and is consistent with hypotheses regarding the extent and nature of tropical to warm temperate European forests during the Eocene. The fossil reinforces the hypothesis that the distribution of Plutoniumidae, once more geographically widespread, has been pruned by extinction. http://zoobank.org/urn:lsid:zoobank.org:pub:ECBF2C04-CA1B-4FBC-A19E-26A0094196EC

Rare species of West Indian aspect in the Holocene of Liverpool Bay and their biogeographic and environmental significance

The Gulf Stream, although not directly responsible for the mild, temperate climate of the British Isles, transports vast quantities of water across the North Atlantic Ocean. An extension of the Caribbean-Loop-Florida current system, this strong current cools and becomes more saline by evaporation as it flows NE across the North Atlantic Ocean. Nevertheless, it is able to transport benthic foraminifera across oceanic distances, the fauna around Bermuda containing many species described from the Caribbean Sea. Examining two cores taken from the shallow middle neritic Holocene Surface Sands Formation of the temperate Liverpool Bay, England, we found rare specimens of eight species recorded also from the neritic of the tropical Caribbean and subtropical Atlantic South Shelf Provinces: Asterigerina carinata, Dyocibicides biserialis, Elphidium discoidale, Nonionoides grateloupii, Quinqueloculina lamarckiana, Reussella atlantica and Sahulia conica. We are confident in our identifications of A. carinata and E. discoidale, but suggest that these names may have been applied to several cryptospecies. Some of these may have been transported on floating phytal debris, A. carinata, which supports algal symbionts, having been recorded at abyssal depths in the eastern North Atlantic. Othersmay have been transported as small propagules (proloculi). Although there may be a constant rain of such specimens into Liverpool Bay, we conclude on the basis of their rarity that the exotic species are unlikely to be able to overwinter there. We suggest, however, that these may have potential as invasive species for Liverpool Bay as climates continue to warm. This is not the earliest instance of transport of exotic species across the North Atlantic. The Late Eocene species Asterocyclina soldadoensis has been recorded from both the southern Caribbean region and offshore Ireland.

Middle Eocene Ostracods from southeast Fayoum area, Egypt: Systematics, paleobathymetry and paleobiogeography

This study deals with the Middle Eocene ostracods from southeast Fayoum area, Egypt. To carry out this investigation, three outcrops are examined, Gebel Elwe El Breig, Gebel Sath El Hadid and Gebel Munqar El-Shinnara. This study is based on the Midawara Formation that consists mainly of fossiliferous limestone, marly limestone and clay. The studied ostracod assemblage includes thirty-one species and subspecies, belonging to twenty-three genera and seventeen families. The ostracod group belonging to Cytheroidea Baird, 1850 represents the most abundant group that reaches 81.99% in Munqar El-Shinnara section, 81.88% in Sath El Hadid section, and 61.12% in Elwe El Breig section. The structure of the investigated assemblages (abundance of ostracods, number of taxa, Fisher's alpha, Shannon index, and equitability) indicates deposition in an environment belonging to the neritic zone. Moreover, this study tries to use the multivariate analyses to distinguish the paleobiogeographic provinces in Tethyan region during the Middle Eocene. These analyses are applied on a matrix consists of some nominated Middle Eocene species from 13 countries. The results point to two distinctive provinces, Southern Tethys Province (Algeria, Tunisia, Libya, Egypt and Jordan) and the Northern Tethys Province (England, Germany, Spain, France, Belgium, Ukraine, Hungary and Turkey). The reasonable similarities between these provinces may reflect a possible connection between both sides of the Tethys during the Middle Eocene age.

The fossil record of Eloeophila (Diptera: Tipuloidea: Limoniidae)

ABSTRACT Eloeophila is a genus of Limoniidae (subfamily Limnophilinae) with 85 extant valid species. So far, only one fossil species has been described: Eloeophila moba Podenas, from Baltic amber (Eocene). Here we have described other species from Baltic amber: Eloeophila eocenica sp. n. We also found that Cladura maculata, an Eocene species described by Scudder in 1894, from Florissant, Colorado, USA, actually belongs to Eloeophila. This species was renamed Eloeophila scudderi nom. nov. With these changes, Eloeophila now has three fossil species.