LUTETIACADER, A PUZZLING NEW GENUS OF CANTACADERID LACE BUGS (HETEROPTERA: TINGIDAE) FROM THE MIDDLE EOCENE MESSEL MAAR, GERMANY

Abstract:  A new genus of cantacaderid lace bugs, Lutetiacader gen. et sp. nov., is described from the lower Middle Eocene of Messel Quarry, Germany. It clearly belongs to the cantacaderid lineage of Tingidae, and is the second known fossil genus of the tribe Cantacaderini (after Paleocader Froeschner). It appears to be most similar to extant species of the genera Nectocader Drake (Brazil) and Teratocader Drake (Malay Peninsula). Lutetiacader occupies a central position with respect to the geographical gap between the ranges of these two extant genera. Its biogeographical significance is discussed.     

Cladogenesis and replacement in the fossil record of Microsyopidae (?Primates) from the southern Bighorn Basin,Wyoming

The early Eocene of the southern Bighorn Basin, Wyoming, is notable for its nearly continuous record of mammalian fossils. Microsyopinae (?Primates) is one of several lineages that shows evidence of evolutionary change associated with an interval referred to as Biohorizon A. Arctodontomys wilsoni is replaced by a larger species, Arctodontomys nuptus, during the biohorizon interval in what is likely an immigration/emigration or immigration/local extinction event. The latter is then superseded by Microsyops angustidens after the end of the Biohorizon A interval. Although this pattern has been understood for some time, denser sampling has led to the identification of a specimen intermediate in morphology between A. nuptus and M. angustidens, located stratigraphically as the latter is appearing. Because specimens of A. nuptus have been recovered approximately 60 m above the appearance of M. angustidens, it is clear that A. nuptus did not suffer pseudoextinction. Instead, evidence suggests that M. angustidens branched off from a population of A. nuptus, but the latter species persisted. This represents possible evidence of cladogenesis, which has rarely been directly documented in the fossil record. The improved understanding of both evolutionary transitions with better sampling highlights the problem of interpreting gaps in the fossil record as punctuations.     

A fossil Halobates from the Mediterranean and the origin of sea skaters (Hemiptera, Gerridae)

Five species of sea skaters, genus Halobates Eschscholtz, are the only insects to have successfully colonized the open ocean. In addition, 38 species are found in sheltered coastal waters throughout tropical Indo-Pacific. The taxonomy of the genus is relatively well known, and the phylogeneuc relationships between extant species have recently been analysed (using cladistic methods). In the present paper, we describe the first fossil species of sea skaters, Halobates ruffoi sp. no v. from the Eocene deposit 'Pesciara di Bolca', in the province of Verona, northeastern Italy (geological age about 45 Myr). The significance of this fossil in setting the time scale for the reconstructed phylogeny and anagenesis of adaptive features of sea skaters, and in understanding the evolution and historical zoogeography of these marine insects is discussed.     

A combined light and scanning electron microscopy study

The uppermost Eocene Florissant Formation, Rocky Mountains, Colorado, has yielded numerous insect, vertebrate and plant fossils. Three previous comprehensive palynological studies investigated sections of lacustrine deposits of the Florissant Formation and documented the response of plant communities to volcanic eruptive phases but overall found little change in plant composition throughout the investigated sections. These studies reported up to 150 pollen and spore phenotypes. In the present paper, we used a taxonomic approach to the investigation of dispersed pollen and spores of the Florissant Formation. Sediment samples from the shale units containing macrofossils were investigated using light microscopy (LM) and scanning electron microscopy (SEM). The general picture of the palynoflora is in agreement with previous studies. However, the combined LM and SEM investigation provides important complementary information to previous LM studies. While a fairly large amount of previous pollen determinations could be confirmed, the purported taxonomic affinities of several pollen phenotypes need to be revised. For example, pollen referred to as Podocarpus or Podocarpidites sp. belongs to the Pinaceae Cathaya, Malus/Pyrus actually belongs to Dryadoideae, pollen of the form genus Boehlensipollis referred to as Proteaceae/Sapindaceae/Elaeagnaceae or Cardiospermum belongs to Sapindaceae but not to Cardiospermum, and pollen of Persicarioipollis sp. B with previously assumed affinities to Polygonaceae actually belongs to Thymelaeaceae. Pandaniidites and one type of Malvacipollis cannot be linked with Pandanaceae and Malvaceae. A few taxa are new records for Florissant (Ebenaceae: Diospyros; Mernispermaceae; Trochodendraceae: Tetracentron). In general, SEM investigations complement the LM palynological studies and improve the identification of dispersed pollen and spores and enable integration of data from dispersed fossil pollen into a wide range of comparative morphological, taxonomic, evolutionary, biogeographic and phylogenetic studies.     

A NEW PRIMITIVE CHALICOTHERE (PERISSODACTYLA,MAMMALIA) FROM THE EARLY EOCENE OF HUBEI, CHINA

'I.DESCR1PTIoNorderPerissodactylaOwen,l848SuperfamilyCbalicotherioideacall,l872'Family?EomoropidaeVret,l958GehusDanjiangiagen.nov.TypespeciesDaniiangiapingigen.etsp-nov.DiagnoaisSma1lprimitivecha1icothere(lengthofM/l=8.3mm),skullshallowwithcranialrostrumrelatively1ong,mandibularhorizontalramusandmandibularsymphysisfairlylongandsha1low,teeth1ow-crowned,dentitionformula:3.l.4.3/3.1.4.3.Premolarnonmolariform,P2/2tIenchant,P4/withincipientmesostyle.M/widerthan1engthwithW-shapedectoIoph,…