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On Baltic amber inclusions treated in an autoclave
Inclusions from Baltic amber processed in an autoclave are described, illustrated, and the various degrees of artificial modifications are commented upon. To inform entomologists and palaeontologists with less experience in amber and inclusions, general information on improved inclusions is given.
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... diagnostic features present and identification to genus level possible. Autoclave processing did not cause serious alterations. Mycetophilidae (Diptera), Mycomyia sp., male, 5.3 mm (Fig. 4) The gnat inclusion is embedded in a multi-layered amber piece is in a somewhat decayed condition, left eye with irregular rounded hole, a damage often seen in eroded inclusions which were not covered totally by resin flow, tarsi and flagellomeres of antenna partly disconnected. Thorax and coxae roasted and amorphous, without any ...
Citations
... The results of this process are apparent from the blackened appendages of the beetle that are distinctly deformed (particularly tibiae and tarsi), and from one of the synincluded Nematocera that has a roasted appearance. For details on the effect of autoclaving on amber fossils see Hoffeins (2012). Using micro-CT, the fossilized beetle body yields a contrast so that its external shape could only be coarsely imaged (Fig. 59). ...
Of the 12 specimens of Calathus -like sphodrine beetles presently known from Baltic and Rovno amber deposits, 11 specimens were investigated using light microscopy, micro-CT scanning, and 3D imaging techniques. For the first time, many significant diagnostic characters of the external morphology and male and female genitalia of Eocene Sphodrini were studied in detail. Based on these data, three fossil species are diagnosed and placed in a natural group characterized by a derived pattern in elytral chaetotaxy and microsculpture and therefore the genus Quasicalathus Schmidt & Will, gen. nov. is described to comprise these species. Due to the presence of a styloid right paramere, Quasicalathus gen. nov. is considered a member of the sphodrine “P clade” of Ruiz et al. (2009). However, given the absence of synapomorphies of any species group of the P clade, the systematic position of Quasicalathus gen. nov. within this clade remains unresolved. The Baltic amber species Calathus elpis Ortuño & Arillo, 2009 is redescribed based on additional, fossil, non-holotype material and transferred to Quasicalathus gen. nov. Identification of the additional C. elpis fossil material remains slightly uncertain due to the non-availability of the holotype for direct comparison coupled with doubts regarding the accuracy of certain character states presented in its original description. Two species are newly described: Quasicalathus agonicollis Schmidt & Will, sp. nov., from Baltic amber, and Q. conservans Schmidt & Will, sp. nov., from Rovno amber.
... So-called "sun-sparks" are disk-shaped cracks created by heating in conjunction with a rapid change in pressure (Dahms, 1906;Wang et al., 2014). Autoclaving (combining heat and pressure) might not only damage amber and change its chemical properties (Wagner-Wysiecka, 2018), but also alter, shrink or darken its inclusions, so that certain characters are hardly visible after treatment (Hoffeins, 2012;Szwedo and Sontag, 2009). Like heating, a bath in boiling oil (e.g. ...
Amber, a natural polymer, is fossil tree resin derived from diverse botanical sources with varying chemical compositions. As such, all amber is susceptible to the effects of light, temperature, relative humidity, and oxygen, as well as exposure to certain chemicals, and will deteriorate over time in collections if left unprotected. Here we review approaches for the conservation, preparation, and imaging of amber specimens and their inclusions, and address indications and causes of amber degradation, as well as recommendations for a suitable storage environment. We also provide updated preparation and embedding protocols, discuss several techniques for imaging inclusions, and address digitization efforts. A stable storage environment is essential to mitigate or avoid deterioration of amber, which often manifests as crazing, spalling, breaking and colour changes. Based on previous conservation studies of fossil resins, we generally recommend storage in a climate-monitored environment with a relative humidity of ca. 50%, 18 °C, and stress that light exposure must be kept to a minimum. For stabilization and anoxic sealing, amber specimens should ideally be embedded in an artificial epoxide resin (EpoTek 301-2 or similar is currently recommended). Amber should not be treated with or stored in vegetable or mineral oils (even for a short time for examination or photography), or come into contact with alcohol, disinfecting agents, hydrogen peroxide, or other destructive solvents or mixtures, since any of these materials can irreversibly damage the amber. Most photography of inclusions for research and digitization purposes can be successfully accomplished using light microscopy. Scanning electron microscopy (SEM) is sometimes used to uncover fine details, but is an invasive method. However, X-ray based methods (utilizing micro computed tomography, or micro-CT) are becoming more frequently used and increasingly indispensable in the examination of minute internal structures of inclusions, and to fully visualize important structures in opaque amber. Micro-CT makes it possible to digitize an inclusion three-dimensionally, and thus enables digital specimen ‘loans.’ Light microscopal images are still widely used in the digitization of amber specimens and are an essential alternative to micro-CT imaging when resources or time are limited. Overall, due to the vulnerability of all fossil resins, we recommend that conservation of amber samples and their inclusions be prioritized.
... Details of the holotype are hardly visible: a milky coating, debris, and the position of specimen in amber is adverse to optimal viewing. The amber of the Hoffeins collection was treated in autoclave before this examination, but without visible thermic modifications (Hoffeins, 2012). One male is in almost perfect condition with a view from the right, particularly of the terminalia. ...
Bruchomyiinae is a subfamily of the Psychodidae (Diptera) with 57 extant and 19 extinct described species (Wagner & Stuckenberg, 2012, 2016). The core distribution area of extant species is the Neotropical region with almost 50 species in four genera. Six species in two genera are known from the Afrotropical region, and four species in one genus from the Oriental region (Polseela et al., 2018; Wagner & Stuckenberg, 2012, 2016). In the Nearctic and the Palearctic regions Bruchomyiinae are almost absent, with species occurrences only along the southern borders with sub-tropical climates.
... Presently, a large fraction of the Baltic amber material available has been treated with an autoclave to improve the transparency and general appearance of the amber (Hoffeins 2012). Unfortunately, this may alter the appearance of the specimens in fairly unpredictable ways, and may destroy much taxonomically relevant information (Hoffeins 2012). ...
... Presently, a large fraction of the Baltic amber material available has been treated with an autoclave to improve the transparency and general appearance of the amber (Hoffeins 2012). Unfortunately, this may alter the appearance of the specimens in fairly unpredictable ways, and may destroy much taxonomically relevant information (Hoffeins 2012). ...
Species of Bibionidae from Baltic amber are reevaluated based on newly discovered material, and a key to the species is given. Bibio succineus sp. nov. is described based on one male specimen, this is the first Bibio named from Baltic amber. The males of Hesperinus electrus Skartveit, 2009 and Penthetria montanaregis Skartveit, 2009 are redescribed. A single, autoclave treated specimen of Penthetria sp. is described but not formally named. Plecia tenuicornis Skartveit, 2009 is found to be a synonym of Plecia hoffeinsorum Skartveit, 2009, this species is recorded for the first time from Rovno amber, and both sexes of the species redescribed. Additional specimens of Plecia clavifemur Skartveit, 2009 and Dilophus crassicornis Skartveit, 2009 are described. Two female specimens probably belonging to the species discussed as Dilophus sp. by Skartveit (2009) are described, but not formally named.
... Up to now, only four species have been described, namely Airaphilus denticollis Ermisch, 1942 (probably belonging to Psammoecus Latreille, 1829), Dendrobrontes popovi Kirejtshuk, 2011, Mistran ot Alekseev & Bukejs, 2016, and Cathartosilvanus necromanticus Alekseev, 2017. Additionally, Silvanus sp. and Nausibius sp. have been reported from the Baltic amber, and the genus Cryptamorpha Wollaston, 1854 has been mentioned from Eocene Bitterfeld amber (Hope, 1836;Berendt, 1845;Menge, 1856;Helm, 1896;Handlirsch, 1908Handlirsch, , 1925Klebs, 1910;Bachofen-Echt, 1949;Larsson, 1978;Spahr, 1981;Hieke and Pietrzeniuk, 1984). ...
... The geological backgrounds of the Baltic and Bitterfeld amber deposits have recently been reviewed (Standke, 2008;Weitschat and Wichard, 2010), and the interconnectedness of these deposits has been assessed on the basis of arthropod inclusions (e.g., Hoffeins and Hoffeins, 2003;Szwedo and Sontag, 2013;Dunlop et al., 2018) and geochemistry (Wolfe et al., 2016). Amber from the former Palmnicken mine (Yatarny settlement, Kaliningrad, Russia) is part of a commercially mined deposit of Baltic amber. ...
A new fossil species of the silvanid flat bark beetle genus
Cathartosilvanus Grouvelle is described and illustrated from Baltic amber. Cathartosilvanus siteiterralevis sp. nov. differs
from recent and fossil congeners in the distinct, sharp denticle found along
its posterior pronotal angle. The phenomenon of specific body parts becoming
disconnected, and the compression of specimens is briefly discussed and
interpreted in the context of amber taphonomy. The specimen under study
appears to be an uncommon case of a weakly sclerotized beetle imago becoming
entrapped in resin shortly after moulting.
... Specimen 1084-4 is an embedded piece of amber that was prepared as per Hoffeins (2001) and is untreated via autoclave. Specimen 1084-5 is a large and unembedded piece of Baltic amber that was treated in an autoclave as per Hoffeins (2012) and polished as per Hoffeins (2001). Images were taken using a Zeiss SteREO Discovery V.20 stereomicroscope with a Plan-Apochromat S 0.63x objective and an AxioCam HRc Rev. 3 digital camera. ...
A new genus and species of pygmy grasshopper (Orthoptera: Tetrigidae) is described from Eocene Baltic amber. Danatettix hoffeinsorum gen. et sp. nov. is assigned to the subfamily Batrachideinae based on antennae with more than 19 antennomeres, sulcate mesofemora, and rectangular paranota. This species is readily distinguished from other batrachideines by a markedly produced vertex, pronotum with divergent internal and external lateral carinae, and highly setiferous female lateral basivalvular sclerite with scabrose integument. The morphology of Danatettix suggests placement within the here defined Tettigidea genus group (comprising Eutettigidea Hancock, 1914, Paurotarsus Hancock, 1900, and Tettigidea Scudder, 1862) and suggests that the latter had diverged from the new Scaria genus group (comprising Eotetrix Gorochov, 2012, Rehnidium Grant, 1956 and Scaria Bolívar, 1887) by the Early Eocene.
... Comparison with main characters of amber Palaeopsylla reveals that it is more similar to P. dissimilis rather than to P. baltica and P. groehni. Amber with P. baltica was treated in autoclave (Hoffeins 2012), chaetotaxy of abdomen is not well preserved and it is a female. The striking feature of P. groehni, a group of spatulate setae on posterior margin of sternite IX, cannot be detected in previously documented images and drawing (JANZEN 2002 figs. ...
... Fossil resins -opposite to inorganic precious stones, can be treated as organic polymers which properties can be modified under defined temperature and pressure conditions. It affects the structure of polymer matrix and the chemical composition of material, for example volatile compounds and water entrapped in matrix are removed [56,57]. Such processes are carried out in autoclaves in the atmosphere of various gases. ...
Natural Baltic amber (succinite) is the most appreciated fossil resin of the rich cultural traditions dating back to prehistoric times. Its unequivocal identification is extremely important in many branches of science and trades including archeology, paleontology, chemistry and finally mineralogical and gemological societies. Current methods of modification of natural succinite are more and more sophisticated making the identification of natural Baltic amber often challenging. In article the systematic analytical approach for identification of natural and modified under different conditions succinite, using mid-infrared spectroscopy (transmission, Drifts and ATR techniques) is presented. The correlation between spectral characteristics and properties of succinite is discussed pointing that the understanding of the nature of changes is the key of identification of this precious material.
... Comparison with main characters of amber Palaeopsylla reveals that it is more similar to P. dissimilis rather than to P. baltica and P. groehni. Amber with P. baltica was treated in autoclave (Hoffeins 2012), chaetotaxy of abdomen is not well preserved and it is a female. The striking feature of P. groehni, a group of spatulate setae on posterior margin of sternite IX, cannot be detected in previously documented images and drawing (JANZEN 2002 figs. ...
... However, such stretching can also occur transversally, with the opposite effect. Some of the effects are similar to those observed for autoclaved amber specimens, especially the increase in relative length of setae, which do not contract as much as other parts (Hoffeins, 2012). Distortion of Mexican amber fossils has been attributed to heating as a result of volcanic activity in the region (Solórzano Kraemer, 2007. ...
Eight pseudoscorpions in amber from Chiapas State, Mexico, are described. These include the first fossil records of the tribe Tyrannochthoniini (Chthoniidae). Paraliochthonius miomaya n. sp. is described from an adult male and a protonymph in separate pieces of amber from Simojovel. The protonymph is the first to be recorded for a species of Paraliochthonius Beier, 1956 and shows that this stage is free-living and non-regressive in this genus. The presence of a Paraliochthonius species in Simojovel amber adds support to the hypothesis that at least part of this amber is derived from a mangrove environment, since the extant epigean species of this genus are restricted to littoral habitats. An unnamed species of Tyrannochthonius Chamberlin, 1929 is described from an adult female in amber from Rio Salado, near Totolapa, Chiapas. Nymphal pseudoscorpions in amber from Simojovel are tentatively assigned to the extant genera Lustrochernes Beier, 1932 (Chernetidae) and Paratemnoides Harvey, 1991 (Atemnidae), and an unidentified genus of Cheliferini (Cheliferidae). The genus Mayachernes Riquelme, Piedra-Jiménez and Córdova-Tabares, 2014, which was erected for the first species of pseudoscorpion to be named from Mexican amber, is synonymized with Byrsochernes Beier, 1959, resulting in the new combination Byrsochernes maatiatus (Riquelme, Piedra-Jiménez and Córdova-Tabares, 2014).
A list is given of extant pseudoscorpions collected close to mangroves at La Cadena and from Hymenaea courbaril trees at Coquitos (Biosphere Reserve La Encrucijada), both in Chiapas State. These include the first Mexican records of the species Americhernes oblongus (Say, 1821) and the genus Dolichowithius Chamberlin, 1931. Paratemnoides elongatus (Banks, 1895) and Trinidatemnus separatus van den Tooren, 2008 are synonymized with P. nidificator (Balzan, 1888) (new subjective synonymies). Trinidatemnus van den Tooren, 2008 therefore becomes a junior synonym of Paratemnoides Harvey, 1991 (new subjective synonymy). The first record of P. nidificator from the Caribbean island of Guadeloupe is given.
