Sciadopitys cladodes from Eocene Baltic amber

The Baltic amber deposit represents the largest accumulation of any fossil resin worldwide and hundreds of thousands of entrapped arthropods have been recovered so far. The source plants of Baltic amber, however, are still controversial, and the botanical composition of the ‘Baltic amber forest’ remains poorly studied. Here, we provide the first unequivocal Baltic amber inclusions of the umbrella pine Sciadopitys (Sciadopityaceae), a genus that has been suggested as the source of succinite (the main variety of Baltic amber) based on chemical analyses. As previously suggested sciadopitoid inclusions must be reconsidered as being notional, representing angiosperm leaves instead, the new fossils are the first unambiguous macrofossil evidence of Sciadopitys from the ‘Baltic amber forest’, and the first pre‐Oligocene macrofossil record of Sciadopitys from Europe. The fossil Sciadopitys cladodes provide new insights into the conifer diversity of the ‘Baltic amber forest’ and broaden the picture of its palaeoecology, indicating the presence of humid swamp to raised bog habitats. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180 , 258–268.     

How diverse were ferns in the Baltic amber forest?

Diverse temperate forest types and a high atmospheric humidity have recently been suggested for the Eocene source area of Baltic amber. However, ferns are astonishingly rare as inclusions in this amber, which is in contrast to other seed‐free land plants, fungi, and lichens. Moreover, the identities of some of the few described putative fern taxa are dubious, and some fossils were even assigned to the Paleozoic seed fern genera Alethopteris, Pecopteris and to the form genus Sphenopteris containing Paleozoic and Mesozoic fern‐like leaf fossils. Here, we review previously described fern inclusions from Baltic amber and identify further fern‐like leaf inclusions as belonging to the extant angiosperm genus Comptonia (sweet ferns, Myricaceae). We conclude that only one taxon, Matonia striata (Matoniaceae), can with confidence be identified as a Polypodiopsida representative. Although “Pecopteris” humboldtiana is so far only known as sterile foliage, its leaf morphology strongly suggests that also this taxon belongs to the Polypodiopsida rather than to any other tracheophyte lineage. We propose accommodating “Pecopteris” humboldtiana in the new genus Berendtiopteris. “Alethopteris” serrata and “Sphenopteris” phyllocladoides are not to be regarded as evidence of ferns from Baltic amber. Reinvestigation of the holotypes of these two taxa did not reveal to which tracheophyte lineages these fossils belong. We suggest that the scarcity of fern remains from Baltic amber may reflect both a relatively low fern diversity in the source area of the fossil resin, and an absence or rarity of epiphytic and climbing ferns as observed in modern temperate forest ecosystems.     

A case of mistaken identification of an amber fossil male strepsipteran (Insecta: Strepsiptera)

A well-preserved specimen of amber Strepsiptera was erroneously described as Stylops neotropicallis Kogan and Poinar, 2010. The taxonomic position of the species was based on a count of six antennomeres (typical of the Stylopidae); however, further observations showed that there are actually seven antennomeres, which places the fossil in the family Myrmecolacidae, and it is herein redescribed in the genus Palaeomyrmecolax Kulicka, 2001. Furthermore, nuclear magnetic resonance spectroscopy analysis of a sample of the amber piece containing the fossil revealed that it was Baltic rather than Dominican amber as originally thought. The fossil was compared with another specimen from Baltic amber in the Poinar collection, which shows close affinity to Palaeomyrmecolax succineus Kulicka, 2001, the type species of the genus. Palaeomyrmecolax neotropicallis (n.comb.) differs from that specimen and seems to differ also from the other four species in the genus Palaeomyrmecolax.     

Characterization of a bacterium isolated from amber

A bacterium has been isolated from Baltic amber, after it was soaked in ethanol and flamed. The bacterium was a Gram-positive aerobic spore-forming rod whose 16S rDNA sequence had a 99.6% homology to that of Bacillus subtilis. Accordingly, the bacterium was identified as a strain in the species Bacillus subtilis. Considering the isolation procedure that was employed, the isolate should not be a contaminant of the contemporary Bacillus population; however, it may not be considered as a bacterium trapped when the amber was formed. These results suggest that amber might contain bacteria that were derived from the environments in which the amber had been located.     

First fossil record of Brachyptera (Plecoptera: Taeniopterygidae) in Eocene Baltic amber

The extant taeniopterygid genus Brachyptera Newport, 1848 is reported from the Eocene Baltic amber for the first time. A new species, Brachyptera dewalti n. sp. (Plecoptera: Taeniopterygidae), is described and illustrated based on a well-preserved female in the amber, distinguished by the presence of three well-developed ocelli, the dark color of antennae, maxillary palps, head, prothorax, and abdominal segments, the CuA vein of forewing with three branches, the nearly rhombus, dark brown postgenital plate, and the four-segmented cerci. It is the fourth taeniopterygid species known from the Baltic amber.     

Species of two paleoendemic sap beetle genera of the Tribe Nitidulini (Nitidulidae: Coleoptera) from the Baltic and Dominican amber

Omositoidea gigantea Schaufuss, 1892 is redescribed; O. pubescens sp. nov. from the Baltic amber, Palaeometopia dominicana gen. et sp. nov. and P. colorata gen. et sp. nov. from the Dominican amber are described. The taxonomic position of the two genera and their probable bionomy are discussed.     

Austrini - a new tribe of Tropiduchidae planthoppers from the Eocene Baltic amber (Hemiptera: Fulgoromorpha)

A new tribe Austrini n. trib. of Tropiduchidae planthoppers from the Eocene Baltic amber is described to comprise Austris raffelis n. gen., n. sp. Fossils ascribed to family Tropiduchidae are discussed.     

Fossil carabids from Baltic amber -II - A new subgenus of Bembidion Latreille 1802 (Coleoptera: Carabidae: Bembidiini)

Bembidion (Archaeophilochthus) christelae a new subgenus and species belonging to the tribe Bembidiini (Coleoptera: Carabidae: Trechinae) preserved in a piece of Baltic amber (Eocene) is described. A comparison with recent fauna is made, and paleobiology of the species is hypothetized.     

First record of ostracods (Crustacea) in Baltic amber

Ostracods were found in two pieces of Baltic amber for the first time. The animals belong to the freshwater genus Cyclocypris. Since Baltic amber was formed during Eocene times in southern Scandinavia, the age of the specimens is estimated at 42–54 million years. As aquatic organisms, ostracods are seldom trapped in amber; it is considered that one specimen, already dead and dried, was either blown onto sticky resin on a plant stem, or washed there by a high flood level, while the other was probably splashed, alive, in a drop of water against the flowing resin, again probably during a flood. Associated faunal remains, including other crustaceans, suggest a coastal palaeoenvironment with some marine as well as freshwater influence.     

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.