A small, “wader-like” bird from the Early Eocene of Messel (Germany)

A small bird with a shorebird-like beak and a very long hind toe is described from the Early Eocene of Messel in Germany. Vanolimicola longihallucis, gen. et sp. nov. is one of the few candidate species for a “wading bird” from Messel, that is, a bird that may have foraged along the shoreline of the ancient lake. A few features indicate a relationship to charadriiform birds and Jacanidae (jacanas) in particular, but charadriiform affinities are only weakly supported. In the preserved skeletal elements, V. longihallucis also resembles the taxon Songzia from the Early Eocene of China, which is considered to be a representative of the Ralloidea (rails and allies). A potential biogeographic significance of the new Messel fossil is strengthened by similar fossils from the North American Green River Formation.     

New specimens of the Eocene Messelirrisoridae (Aves: Bucerotes), with comments on the preservation of uropygial gland waxes in fossil birds from Messel and the phylogenetic affinities of Bucerotes

Exceptionally well-preserved new specimens of the Messelirrisoridae (Aves: Bucerotes), which show previously unknown features of the osteology and feathering of these tiny birds, are described from the Middle Eocene of Messel in Germany. Most notably in one of the new specimens the wing and tail feathers are excellently preserved and even show the former color pattern of the tail. A cream-colored substance in some specimens most likely constitutes fossilized uropygial gland waxes. For the first time, the phylogenetic affinities of the Messelirrisoridae are evaluated in a cladistic analysis, based on 122 characters and 34 extant and fossil taxa. The results of this analysis support the earlier hypothesis that Messelirrisoridae are stem lineage Upupiformes, i.e. the sister taxon of the clade including extant hoopoes (Upupidae) and woodhoopoes (Phoeniculidae). The analysis further supports sister group relationship between Bucerotes (Upupiformes + Bucerotidae [hornbills]) and Piciformes (woodpeckers and allies), although it is detailed that one of the recently proposed apomorphies of the clade (Bucerotes + Piciformes) is absent in the Messelirrisoridae.     

The first New World occurrence of the Eocene birdPlesiocathartes (Aves: ?Leptosomidae)

Two new species of the Eocene avian taxonPlesiocathartes (Aves: ?Leptosomidae) are described. They are similar in size and overall appearance to other members of the genus, as well as to the extant Madagascan cuckoo-rollerLeptosomus discolor. So far, putative fossil Leptosomidae have been found only in the Eocene European de-posits of Messel, Geiseltal, Quercy, and London Clay. Both new species are from the Lower Eocene Green River Formation (USA) and thus the first New World representatives of this taxon.     

Elucidating the affinities and habitat of ancient, widespread Cyperaceae: Volkeria messelensis gen. et sp. nov., a fossil mapanioid sedge from the Eocene of Europe

The sedges (family Cyperaceae) are an economically and ecologically important monocot group dating back at least to the Paleocene. While modern genera are mostly unknown before the Oligocene, several extinct taxa are recognized as the earliest sedges. Their affinities have been unclear until now, because they are found as isolated, often abraded fruits or endocarps. Exceptionally preserved sedge fossils from the Middle Eocene of Messel, Germany yield more characters for identification. Fossil cyperacean infructescences with in situ pollen are recognized for the first time and show features of the early-divergent mapanioid sedges. Pollen resembles that of tribe Hypolytreae. Comparisons with extant taxa suggest the closest affinities with Hypolytrum and Mapania. However, the Messel fossils represent a distinct taxon, Volkeria messelensis gen. et sp. nov. Without the additional characters of infructescence and pollen, the Messel fruits would have been placed in the extinct genus Caricoidea, a typical Eocene sedge that was widespread across Eurasia. Similarities of fruit structure suggest that Caricoidea was also a mapanioid sedge. Mapanioid sedges are found today in tropical wet forests and swamps, a distribution suggesting that early sedges occupied a similar habitat, unlike many modern sedges, and were not precursors to open grassland vegetation.     

Fossil water‐penny beetles (Coleoptera: Psephenidae: Eubrianacinae) from the Eocene of Europe,with remarks on their phylogenetic position and biogeography

Abstract: A species of water‐penny beetles is recorded from larval instars from the Middle Eocene Messel pit fossil site in Germany. This species clearly belongs to the psephenid subfamily Eubrianacinae, but its precise systematic affinities remain unclear. It is the second fossil species of this taxon recorded from Europe. The holotype of the first fossil species, Eubrianax vandeli Bertrand and Laurentiaux, 1963, is lost. The high number of fossil specimens from Messel allowed discussion of stratigraphic and spatial occurrence of the eubrianacine species in the Messel pit, but its larval ontogeny could not be unravelled. Because of the high number of fossils and their wide occurrence, it is inferred that the species from Messel gen. sp. 1 was an autochthonous faunal element of the Eocene Lake Messel, which might indicate that some parts of the former Lake Messel had a shore area with stones. The analysis of the phylogenetic position of both Eocene eubrianacine species showed that their phylogenetic placement cannot be resolved because preservational influences limit the evaluation of characters. The historical biogeography of Psephenidae and Eubrianacinae is analysed and discussed. The fossil record shows that psephenid beetles have fossil members occurring outside their current distribution range, so interpretations of their biogeography based only on extant members can be misleading.     

The early Eocene birds of the Messel fossil site: a 48 million‐year‐old bird community adds a temporal perspective to the evolution of tropical avifaunas

Birds play an important role in studies addressing the diversity and species richness of tropical ecosystems, but because of the poor avian fossil record in all extant tropical regions, a temporal perspective is mainly provided by divergence dates derived from calibrated molecular analyses. Tropical ecosystems were, however, widespread in the Northern Hemisphere during the early Cenozoic, and the early Eocene German fossil site Messel in particular has yielded a rich avian fossil record. The Messel avifauna is characterized by a considerable number of flightless birds, as well as a high diversity of aerial insectivores and the absence of large arboreal birds. With about 70 currently known species in 42 named genus‐level and at least 39 family‐level taxa, it approaches extant tropical biotas in terms of species richness and taxonomic diversity. With regard to its taxonomic composition and presumed ecological characteristics, the Messel avifauna is more similar to the Neotropics, Madagascar, and New Guinea than to tropical forests in continental Africa and Asia. Because the former regions were geographically isolated during most of the Cenozoic, their characteristics may be due to the absence of biotic factors, especially those related to the diversification of placental mammals, which impacted tropical avifaunas in Africa and Asia. The crown groups of most avian taxa that already existed in early Eocene forests are species‐poor. This does not support the hypothesis that the antiquity of tropical ecosystems is key to the diversity of tropical avifaunas, and suggests that high diversification rates may be of greater significance.     

Eocene fossil is earliest evidence of flower-visiting by birds

Birds are important pollinators, but the evolutionary history of ornithophily (bird pollination) is poorly known. Here, we report a skeleton of the avian taxon Pumiliornis from the middle Eocene of Messel in Germany with preserved stomach contents containing numerous pollen grains of an eudicotyledonous angiosperm. The skeletal morphology of Pumiliornis is in agreement with this bird having been a, presumably nectarivorous, flower-visitor. It represents the earliest and first direct fossil evidence of flower-visiting by birds and indicates a minimum age of 47 million years for the origin of bird–flower interactions. As Pumiliornis does not belong to any of the modern groups of flower-visiting birds, the origin of ornithophily in some angiosperm lineages may have predated that of their extant avian pollinators.     

New specimens of the early Eocene stem group galliform Paraortygoides (Gallinuloididae), with comments on the evolution of a crop in the stem lineage of Galliformes

Two new specimens of the fossil stem group galliform Paraortygoides messelensis Mayr 2000 (Gallinuloididae) are described from the Middle Eocene of Messel in Germany, including a complete skeleton in which the hitherto unknown skull of this species is preserved. The shorter and more protruding crista deltopectoralis of the humerus, also for the first time visible in one of the new specimens, shows gallinuloidids to be the sister taxon of all other, extinct and extant, galliform birds. Gallinuloidids distinctly differ from modern Galliformes in several other plesiomorphic osteological features, mainly of the pectoral girdle, of which the absence of a spina interna on the sternum is here reported for the first time. It is assumed that major evolutionary transformations in the stem lineage of Galliformes are related to the evolution of a large crop, which appears to have been absent in gallinuloidids. The vegetarian food component of gallinuloidids thus probably mainly consisted of soft plant matter rather than coarse material such as seeds.     

Ein Archaeotrogon (Aves: Archaeotrogonidae) aus dem Mittel-Eoz?n der Grube Messel (Hessen, Deutschland)?

Zusammenfassung Ein Vogel aus dem Mittel-Eozän der Grube Messel (Hessen, Deutschland) wird als neue Gattung und Art der Archaeotrogonidae Mourer-Chauviré 1980 beschrieben (incertae sedis). Die Exemplare aus Messel wären die ersten artikulierten Skelette dieser Familie.Hassiavis laticauda n. gen. n. sp. unterscheidet sich vor allem im Bau des Coracoids von der GattungArchaeotrogon Milne-Edwards 1892. Besonders bemerkenswert ist die ausgezeichnete Erhaltung der Flügel- und Schwanzbefiederung einiger Exemplare. Einige Schwanzfedern des Holotypus zeigen eine Querbänderung, welche möglicherweise auf die ursprüngliche Pigmentierung dieser Federn zurückzuführen ist. Die phylogenetische Stellung der Archaeotrogonidae wird diskutiert. Zur Zeit sind keine Synapomorphien bekannt, welche diese Familie mit einer der bestehenden Ordnungen verbinden.

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An Archaeotrogon (Aves: Archaeotrogonidae) from the Middle Eocene of the Grube Messel (Hessen, Germany)?

Summary A bird from the Middle Eocene of the Grube Messel (Hessen, Deutschland) is described as a new genus and species of the Archaeotrogonidae Mourer-Chauviré 1980 (incertae sedis). The specimens from Messel would be the first articulated skeletons of this family.Hassiavis laticauda n. gen. n. sp. is distinguished from the genusArchaeotrogon Milne-Edwards 1892 in the morphology of the coracoid. The excellent preservation of the wing feathers and those of the tail in several of the specimens is exceptional. Some tail feathers of the holotype are barred, which might be traced back to the original pigmentation of these feathers. The phylogenetic position of the Archaeotrogonidae is discussed. At present no synapomorphies are known, which could set up a closer relationship between this family and one of the existing orders.

     

Eolacertidae: a new extinct clade of lizards from the Palaeogene; with comments on the origin of the dominant European reptile group – Lacertidae

We describe a new lizard taxon, Stefanikia siderea gen. et sp. nov., from the early-middle Eocene locality of Messel in Germany based on a nearly complete skeleton, which we studied using μCT methods. It shares many characters with the Eocene taxon Eolacerta, which is broadly distributed in the Eocene of central and Western Europe, but is much smaller and shows several important anatomical differences. The new discovery sheds light on the paleodiversity of these lizards in the Eocene of Europe, and the new family name Eolacertidae is proposed to encompass Eolacerta and Stefanikia. The relationships of Eolacerta have been intractable. Our phylogenetic analyses confirm that Eolacertidae is a member of the clade Lacertiformes and provide strong support for a sister-group relationship to Lacertidae. In some places, skin impressions are preserved, displaying the body scalation. As such, the exquisitely preserved specimens of Eolacertidae from Messel provide new insight into the morphology and ecology of lizards on the stem of Lacertidae, Europe’s dominant group of living reptiles.

http://zoobank.org/urn:lsid:zoobank.org:pub:DFD01563-A913-4286-B64B-E0912474FD08     

New species of Primozygodactylus from Messel and the ecomorphology and evolutionary significance of early Eocene zygodactylid birds (Aves,Zygodactylidae)

Zygodactylids (Zygodactylidae) are the extinct sister taxon of passerines (Passeriformes) and among the more abundant small arboreal birds in the early Eocene German fossil site Messel. Four species of the taxon Primozygodactylus have previously been identified and here two new species are described. In addition, new fossils of the poorly known P. eunjooae are reported. The fossils corroborate the presence of two very long central tail feathers for Primozygodactylus, and the feathering of the taxon corresponds with that of extant birds foraging in scrub and undergrowth. Species diversity of zygodactylids falls short of that of passerines, the most species-rich extant avian clade, and in bill shapes they also do not reach the diversity seen in extant Passeriformes. Because zygodactylids closely resemble passerines in skeletal morphology, the evolutionary success of passerines is unlikely to be due to particular skeletal features. Passerines and zygodactylids coexisted in Europe from the early Oligocene to the middle Miocene, and both groups probably differed in ecological characteristics. The zygodactyl foot of zygodactylids may have represented an adaptation for clinging to tree trunks, and if nesting in tree cavities, zygodactylids may have succumbed to competition for safe nesting places with avian or mammalian competitors.

http://zoobank.org/urn:lsid:zoobank.org:pub:7F142141-7E1F-4568-89BF-E2363D128C36     

New fossil ants of the subfamily Myrmeciinae (Hymenoptera, Formicidae) from Germany

Two new fossil members of the subfamily Myrmeciinae are described: Archimyrmex wedmannae, sp. nov (Grube Messel, Germany, Middle Eocene) and Prionomyrmex wappleri, sp. nov. (Rott, Germany, Late Oligocene). Members of the genus Archimyrmex were known earlier from Eocene deposits of the United States and Argentina, and members of the genus Prionomyrmex were known from Late Eocene Baltic amber.     

Squamate reptiles from the middle Eocene of Lissieu (France). A landmark in the middle Eocene of Europe

In Europe, faunas of squamates (lizards and snakes) from the middle Eocene are very poorly known, with the exception of those from the level MP 16 (latest middle Eocene). From the MP 11-MP 15 interval, squamates were previously reported only from Messel (MP 11, earliest middle Eocene) and from the untere and obere Mittelkohle of Geiseltal (MP 12 and MP 13 respectively) in Germany. The present report describes the middle Eocene assemblage of squamates from Lissieu (France), the first fauna reported from the level MP 14. Whereas fossils from Messel and Geiseltal are mostly articulated skeletons, fossils from Lissieu are represented by disarticulated bones; such fossils may be more easily compared to those from other Cenozoic localities, in which bones are almost always disarticulated. The fauna from Lissieu is more diverse than those from the Geiseltal sites and approximately as diverse as that from Messel as they are presently known; it is comprised of 17 distinct taxa. These taxa cannot be all identified to the species or genus level. They belong to iguanids, gekkonids, lacertids, anguids, thecoglossan platynotans, ophidians incertaesedis, boids, ?tropidophiines, “tropidophiids” incertaesedis, booids incertaesedis, and perhaps russellophiids. The fauna includes several new taxa but only a presumed tropidophiine snake may be named on the basis of the available material. The fauna from Lissieu is a mixture of taxa restricted to the middle Eocene and taxa known from older or younger levels. Taxa shared by Lissieu and the few other localities from the middle Eocene of Europe are rare. This fauna from Lissieu represents a stratigraphical landmark for the middle Eocene.     

New spiders in Upper Cretaceous amber from New Jersey in the American Museum of Natural History (Arthropoda: Araneae)

The oldest described fossils of the extant spider family Araneidae (Araneinae; gen. et sp. indet.), the extant genus Orchestina (Oonopidae; O. sp. indet.) and the new fossil genus Palaeosegestria (Segestriidae; P. lutzzii gen. et sp. nov.) are presented from Upper Cretaceous amber of New Jersey. The known fossil range of the extant family Araneidae is extended approximately 50 myr from the previously oldest described araneid from the Middle Eocene oil shales of the Messel pit in Hesse, Germany. The fossil range of the extant genus Orchestina is also extended 50 myr from the previously oldest described specimen in Eocene Baltic amber.     

Caught in the act: the first record of copulating fossil vertebrates

The behaviour of fossil organisms can typically be inferred only indirectly, but rare fossil finds can provide surprising insights. Here, we report from the Eocene Messel Pit Fossil Site between Darmstadt and Frankfurt, Germany numerous pairs of the fossil carettochelyid turtle Allaeochelys crassesculpta that represent for the first time among fossil vertebrates couples that perished during copulation. Females of this taxon can be distinguished from males by their relatively shorter tails and development of plastral kinesis. The preservation of mating pairs has important taphonomic implications for the Messel Pit Fossil Site, as it is unlikely that the turtles would mate in poisonous surface waters. Instead, the turtles initiated copulation in habitable surface waters, but perished when their skin absorbed poisons while sinking into toxic layers. The mating pairs from Messel are therefore more consistent with a stratified, volcanic maar lake with inhabitable surface waters and a deadly abyss.     

A reassessment of Eocene parrotlike fossils indicates a previously undetected radiation of zygodactyl stem group representatives of passerines (Passeriformes)

In the past years, various Eocene fossil birds were described as stem group representatives of the zygodactyl Psittaciformes (parrots). These birds show quite disparate morphologies, which cast some doubt on the correct assignment of all of them to the psittaciform stem group. A reassessment of their affinities is further needed, because it was recently proposed that among extant birds, Psittaciformes and Passeriformes (passerines) form a clade and that passerines possibly derived from a zygodactyl ancestor. Here, phylogenetic analyses are performed, which for the first time also include representatives of the Zygodactylidae, the extinct zygodactyl sister taxon of the Passeriformes. The early Eocene Psittacopes was originally described as a stem group representative of Psittaciformes. However, none of the present analyses supported psittaciform affinities for Psittacopes and instead recovered this taxon in a clade together with zygodactylids and passerines. Also part of this clade are the early Eocene taxa Pumiliornis and Morsoravis, and it is detailed that Psittacopes and the long‐beaked and presumably nectarivorous Pumiliornis, with which it has not yet been compared, are very similar in their postcranial osteology. The present analysis corroborates the hypothesis of a zygodactyl stem species of passerines. To account for these results, Psittacopes is here assigned to a new higher‐level taxon and a new name is also introduced for the clade including Zygodactylidae and Passeriformes.     

A small stem-galliform bird (Aves: Paraortygidae) from the Eocene of Uzbekistan

Landfowl (order Galliformes) are among the most characteristic birds of the modern avian faunas, but their early evolutionary history is insufficiently known. The diversity of previously described Eocene galliforms implies a great role of Eocene diversification in the early evolution of this group. However, almost nothing is known about the Eocene diversity of galliforms in Asia, even though this large continent with a variety of habitats might have played a significant role in their early evolution. Here we describe a partial coracoid from the Lutetian–Bartonian of Uzbekistan, which is the oldest diagnosable galliform bird in Asia, and is further the first landbird known from this geographical area. The specimen displays a unique morphology with few autapomorphies and an unexpected combination of similarities with the African genus Scopelortyx and Eurasian Paraortyx, and hence is described as a new taxon, Xorazmortyx turkestanensis gen. et sp. nov., within the extinct family Paraortygidae, being the first Asian representative of this clade. Similarities with the African genus Scopelortyx indicate a connection of land bird faunas between northern Africa/Arabia and Asia in the middle Eocene. Better dispersal abilities of the early galliforms Paraortygidae are inferred from the osteology of their pectoral girdle and the humerus, which do not show adaptations to the powerful burst take off (escape flight), characteristic of most modern Phasianidae.     

EOCENE RECORDS OF BEE FLIES (INSECTA, DIPTERA, BOMBYLIIDAE, COMPTOSIA): THEIR PALAEOBIOGEOGRAPHIC IMPLICATIONS AND REMARKS ON THE EVOLUTIONARY HISTORY OF BOMBYLIIDS

Abstract:  The first fossil records of Holarctic representatives of the genus Comptosia Macquart, 1840 from the middle Eocene Messel Pit, Germany, and the upper Eocene of Florissant, USA, are reported. The fossil from Messel, Comptosia pria sp. nov., is represented by a well-preserved wing, displaying characteristic wing venation, remains of the second wing and elements of the thorax. The Florissant fossil, C. miranda comb. nov., is preserved almost completely with both wings and most parts of the body visible. Extant members of the genus Comptosia are currently found only in Australia, and close relatives are known from southern South America. Previously this group of genera has been thought to be of Gondwanan origin, but these Eocene fossil representatives of Comptosia from the Holarctic region argue against this interpretation, and suggest that Comptosia and its relatives were more widespread in both Northern and Southern hemispheres during the Palaeogene. The fossil record of bee flies suggests a major radiation of bombyliids in the late Cretaceous or early Cenozoic. This assumption is supported by the comparatively young geological age of many bombyliid host taxa. A key factor driving the specialization of many bombyliid larvae on ground-dwelling hosts may have been avoidance of competition with tachinid flies and parasitic hymenopterans.     

Exceptionally preserved plant parenchyma in the digestive tract indicates a herbivorous diet in the Middle Eocene bird <Emphasis Type="Italic">Strigogyps sapea</Emphasis> (Ameghinornithidae)

The holotype skeleton of the avian species Strigogyps sapea from the Middle Eocene of Messel preserves remains of the digestive tract that have not been studied so far. The crop content of the specimen includes numerous densely packed, tiny spherules containing large cavities. These peculiar structures match well with previously described fossil plant parenchyma cells with starch grain moulds. We hypothesize that the spherule layer represents plant parenchyma ingested by the bird, and that the spherules themselves are casts of cytoplasm with storage organelles. Our study provides a further example of exceptional soft tissue preservation in Messel vertebrates and shows that Strigogyps was at least facultatively herbivorous. A herbivorous diet of Strigogyps is also indicated by the fact that the crop content includes seed remains, and it constitutes further evidence against previously hypothesized close affinities between the taxon and the carnivorous Phorusrhacidae.     

A NEW SPECIES OF MOERITHERIUM (PROBOSCIDEA, MAMMALIA) FROM THE EOCENE OF ALGERIA: NEW PERSPECTIVES ON THE ANCESTRAL MORPHOTYPE OF THE GENUS

Abstract:  A new species of Moeritherium (Proboscidea, Mammalia), M. chehbeurameuri sp. nov., is described from remains discovered in the early late Eocene locality of Bir El Ater, Algeria. Although mainly represented by isolated teeth, it shows distinct synapomorphies which justify its attribution to the genus Moeritherium , together with exclusive features that led to the creation of the new species. The main characteristic of this new taxon is the almost complete lophodonty shown by its molars, while Moeritherium is commonly regarded as a bunolophodont to bunodont taxon. In addition to this lophodonty, this new taxon shows anatomical features as yet unknown for the genus, but often met within lophodont early proboscidean taxa such as Phosphatherium escuilliei and Numidotherium koholense . Although a revision of the whole genus Moeritherium is outside the scope of this paper, the main controversies and discussion about the definition of species within the genus Moeritherium are discussed. The surprising lophodonty of M. chehbeurameuri , together with its small size, its early late Eocene age and the weak molarization of its P₃ support the hypothesis of a lophodont hypothetical ancestor for moeritheres, and therefore strengthen the growing hypothesis of a lophodont dental ancestral morphotype for proboscideans.