First Baltic amber megapodagrionid damselfly (Odonata: Zygoptera)

Electropodagrion szwedoi n. gen., n. sp., first Baltic amber megapodagrionid damselfly, is described. The European and North American fossils document a very high diversity and a much wider distribution of this group of damselflies during the Cenozoic than today. A checklist of described fossil species of damselflies of the family Megapodagrionidae is given.     

A new record of Thaumastobombus andreniformis Engel 2001 in Eocene amber (Hymenoptera: Apidae)

A new specimen of the rare fossil bee Thaumastobombus andreniformis Engel 2001 (Apidae: Apinae: Electrapini) is reported and figured from middle Eocene (Lutetian) Baltic amber. The new specimen, a female of the worker caste, agrees in every respect with the holotype except some morphometric differences. These minor size differences are likely related to the degree of sociality of T andreniformis.     

Implications of imaginal-size variation over the flight period in stoneflies (Plecoptera)

In the present study, the decrease in the mean size of specimens over the species flight period in Plecoptera (12 species, 5 families) was analysed, revealing a significant decrease in the adult mean size, for both males and female, in almost all the species without an extended flight-period pattern. Some of the data show that, in addition to temperature, other regulatory factors must govern these variations. Data support the explanation previously proposed for other insect groups that the individuals with appropriate development emerge at the beginning of the flight period or slightly afterwards, when environmental conditions are suitable, whereas individuals with suboptimal size emerge later trying to increase in size but under pressure to emerge during a specific period of the year. Nevertheless, our data suggest that maximum size does not necessarily coincide with the peak flight period (maximum reproductive possibility).     

Redescription of Eatonisca tertiaria Meunier 1905 from Baltic amber (Diptera: Psychodidae: Trichomyiinae)

Eatonisca tertiaria Meunier 1905, is redescribed from the Eocene Baltic amber, with details of the eyes, antennae and male genitalia structure provided. This fossil is placed within Trichomyiinae, and shares several plesiomorphies with Psychodinae, Phlebotominae, and Sycoracinae.     

Biometric analysis of Nummulites bahariyaensisn. sp. (Nummulites partschi group) from the Bartonian of Bahariya Oasis,Egypt

Nummulites bahariyaensisn. sp., typical of Nummulites partschi group, Nummulites gizehensis subgroup, is biometrically studied, described and photographed through both generations from El-Hamra Formation, Garra El Hamra, northern plateau of Bahariya Oasis, Western Desert of Egypt. From the biometric analysis, N. bahariyaensis is phylogenetically parallel to Nummulites lyelli, both of Bartonian age based on the presence of Nummulites decrouezae and Nummulites aff. pulchellus which were dated as Bartonian from Gebel Mokattam, the species which is equated with those from Naalon stratigraphic section, Fayum, by Morsi et al. (2003). Nummulites bahariyaensis could be compared with Nummulites champollioni as both are thick in the microspheric generation. However, the phylogeny of the present new species should be searched on. The described species spans SBZ 17 of the Shallow Benthic Zones of Serra-Kiel et al. (1998, Bull Soc Geol France 169(2):281–299), which denotes an Early Bartonian ( = Biarritzian sensu Hottinger and Schaub 1960, Eclogae Geol Helv 53: 453–479). At Garra El Hamra, El-Hamra Formation with N. bahariyaensis unconformably overlies the Qazzun Formation (Late Ypresian) emphasising that the Lutetian and the top part of Ypresian possibly are missing.http://zoobank.org/22549148-0BD6-4097-A22C-01CA614B5CE1     

What is Nummulites depressus Kenawy 1978? Evolution of Nummulites fabianii group in the Middle Eocene of Egypt

New species Nummulites vetustufabianiin. sp. is described from the El Hamra Formation, Gara El Hamra section Bahariya Oasis Western Desert. The biometrical measurements include maximum and minimum diameter of the successive radii and heights of whorls, length/height ratio, number of chambers and the marginal cord thickness of each whorl for the megalospheric generation as well as the diameter of proloculus were elaborated to differentiate between some allied granulated species such as Nummulites depressus, Nummulites decrouezae, Nummulites cuvillieri and N. vetustufabianiin. sp.Nummulites fabianii group has lateral distribution for the entire Tethys basin, hence such biometrical studies are needed to emphasise the polyphyletic nature of the group.     

An intertidal balanomorph Hexaminius venerai sp. nov. (Austrobalanidae) colonizing a log of Podocarpoxylon from the La Meseta Formation (Eocene), Seymour Island,Antarctica: a glimpse of Antarctic antiquity

Abstract

The sessile barnacle Hexaminius venerai sp. nov. (Tetraclitoidea: Austrobalanidae) is described from the middle Eocene La Meseta Formation of Seymour Island, Antarctic Peninsula. Hexaminius venerai sp. nov. is the earliest known record of the genus in the Antarctic, the first occurrence of Hexaminius from outside Australian waters and the first record of a fossil cirripede attached to the substrate from the Antarctic. Exceptional preservation of more than 200 specimens, some of which retain opercula within the shell, is discussed. In life, the cirripedes were attached to a tree trunk tentatively identified as Podocarpoxylon, a South Hemisphere conifer. Hexaminius venerai sp. nov. is a survivor of an early phase in balanid radiation, prior to the development of strong radially-interlocked parietes.https://zoobank.org/urn:lsid:zoobank.org:pub:EAA2EB5C-BC57-41FA-93A0-046AF5FD59EB     

Taxonomic significance of asymmetrical helmet and lance bristles in the genus Mallomonas (Synurophyceae) and their discovery in Eocene lake sediments

Complex bristle types formed by species in the genus Mallomonas include those with helmet or lance-shaped apices. The ornamentation on each side of the helmet has been thought to be equivalent or symmetrical, whereas on a lance-shaped bristle an expanded portion folds over one side of the shaft to form an asymmetrical structure. We describe, for the first time, helmet bristles with a distinctly asymmetrical design, also formed by the folding of a siliceous membrane over one side of the helmet. We postulate that the asymmetrical helmet represents a structure that combines the formation of a symmetrical helmet and a lance-shaped design on the same bristle. Further, we report structurally similar asymmetrical helmet bristles, lance-shaped bristles and scales that are unambiguously assigned to Mallomonas asmundiae in Middle Eocene sediments from a maar lake in northern Canada, supporting the hypothesis that scale and bristle morphology in the Synurophyceae has undergone extensive prolonged evolutionary stasis. Given differences in scale morphology and the presence of asymmetrical helmet bristles, we transfer the North American endemic Mallomonas acaroides var. muskokana to the rank of species. Further, we formally describe Mallomonas dispar and M. lancea, fossil species with asymmetrical helmet bristles and lance-shaped bristles, respectively. The taxonomic and biogeographic significance of asymmetrical and lance-bearing bristles is discussed.     

Chemical evidence of preserved collagen in 54-million-year-old fish vertebrae

Collagens are the most abundant proteins in the animal kingdom. They form the structural framework of connective tissues such as bones, tendons and skin, and play important biomechanical role in supporting tissue functions. The preservation of collagen in deep time is a topic of intense debate. Here we provide indisputable evidence for the presence of collagen in early Eocene fish vertebrae using online pyrolysis comprehensive two dimensional gas chromatography time-of-flight mass spectrometry (py-GC×GC-TOFMS) and immunofluorescence analysis. The presence of cyclic dipeptides such as diketodipyrrole, 2,5-diketopiperazine of proline-proline and 2,5-diketopiperazine of proline-glycine along with other nitrogen-bearing molecules in the pyrolysis products of the studied fossils unequivocally demonstrate that collagen can withstand degradation and diagenetic alteration. Immunofluorescence study also confirms the presence of collagen-I in the fossilized fish vertebrae. Contrary to common opinion, the present findings suggest that the preservation of collagen in fossilized soft tissues is not rare. We propose that one of the essential factors controlling preservation of collagen is the establishment of a suitable microenvironment within the fossil, inhibiting diagenetic alteration including microbial decay.