206 research outputs found
The first fossil cyphophthalmid harvestman from Baltic amber
The first fossil cyphophthalmid harvestman (Opiliones: Cyphophthalmi) from Palaeogene (Eocene) Baltic amber is described. This is only the third fossil example of this basal harvestman lineage; the others being from the probably slightly younger Bitterfeld amber and the much older, early Cretaceous, Myanmar (Burmese) amber. Although incomplete and lacking most of the appendages, the new Baltic amber fossil can be identified as a female. The somatic characters preserved, especially spiracle morphology and the coxo-genital region, allow it to be assigned with some confidence to the extant genus Siro Latreille, 1796 (Sironidae). This fossil is formally described here as Siro balticus sp. nov. It resembles modern North American Siro species more than modern European ones, and can be distinguished principally on its relatively large size and the outline form of the body
The sejugal furrow in camel spiders and acariform mites
Camel spiders (Arachnida: Solifugae) are one of the arachnid groups characterised by a prosomal dorsal shield composed of three distinct elements: the pro-, meso- and metapeltidium. These are associated respectively with prosomal appendages one to four, five, and six. What is less well known, although noted in the historical literature, is that the coxae of the 4th and 5th prosomal segments (i.e. walking legs 2 and 3) of camel spiders are also separated ventrally by a distinct membranous region, which is absent between the coxae of the other legs. We suggest that this essentially ventral division of the prosoma specifically between coxae 2 and 3 is homologous with the so-called sejugal furrow (the sejugal interval sensu van der Hammen). This division constitutes a fundamental part of the body plan in acariform mites (Arachnida: Acariformes). If homologous, this sejugal furrow could represent a further potential synapomorphy for (Solifugae + Acariformes); a relationship with increasing morphological and molecular support. Alternatively, outgroup comparison with sea spiders (Pycnogonida) and certain early Palaeozoic fossils could imply that the sejugal furrow defines an older tagma, derived from a more basal grade of organisation. In this scenario the (still) divided prosoma of acariform mites and camel spiders would be plesiomorphic. This interpretation challenges the textbook arachnid character of a peltidium (or âcarapaceâ) covering an undivided prosoma
[Buchbesprechung:] Jörg WUNDERLICH (Hrsg.) (2004): Fossil Spiders in Amber and Copal. Fossile Spinnen in Bernstein und Kopal
Buchbesprechun
Ein Geburtstag, eine Taufe und eine Festschrift: Zehn Jahre "AraGes" in Frankfurt
Festschrift zum 10. Geburtstag der Arachnologischen Gesellschaft Frankfurt/M
Faunistic spider collections in the Museum fĂŒr Naturkunde Berlin: The collection of Erich Hesse
The âHesse collectionâ of spiders (Araneae) and harvestmen (Opiliones) in the Museum fĂŒr Naturkunde Berlin is documented. Biographical notes on Erich Hesse â a former arachnid curator at the museum (1921â1940) â are provided. The âHesse collectionâ was actually put together by other workers, and can be broadly divided into two parts. One comes from Bielinek (= Bellinchen) on the Polish side of the Oder Valley (West Pommerania); now part of the âUnteres Odertalâ National Park. This Bielinek material includes notable records of Heriaeus oblongus Simon, 1918 and Gibbaranea ullrichi (Hahn, 1835). The other part of the collection comes from Colbitz-Letzlinger Heide in Saxony-Anhalt, Germany. Notable here are Pistius truncatus (Pallas, 1772) and Philodromus buchari KubcovĂĄ, 2004; the latter representing the first record of this species for Saxony-Anhalt
Observations on regeneration of the pedipalp and legs of scorpions
An Opisthacanthus asper (Peters, 1861) (Hormuridae) shows a relatively rare example of pedipalp regeneration in which the lost tibia and tarsus was replaced by a smaller, curved element of uncertain homology to either the fixed or free finger. A comparable abnormal palp described in the literature hints that pedipalps can only regenerate a structure of this form, regardless of the site of amputation. An Olivierus caucasicus (Nordmann, 1840) (Buthidae) is described in which claws (pretarsus) of leg III regenerated directly at the distal end of the tibia, while in leg IV the claws regenerated at the end of a truncated section of the metatarsus. This supports previous observations that scorpions can only regenerate the pretarsus of the leg, again irrespective of where on the limb the original breakage occurred
On the placement of the Baltic amber harvestmanGonyleptes nemastomoides Koch & Berendt, 1854, with notes on the phylogeny of Cladonychiidae (Opiliones, Laniatores, Travunioidea)
The Baltic amber (Palaeogene: Eocene) harvestman Gonyleptes nemastomoides Koch & Berendt, 1854 (Arachnida: Opiliones), currently misplaced at both the genus and family level, is transferred to the extant family Cladonychiidae and assigned to a new genus, Proholoscotolemon n. gen. The families Gonyleptidae and Phalangodidae are hereby removed from the known harvestman fossil record. Although the type specimen of G. nemastomoides is poorly preserved, the form of the diagnostic hind tarsal claw is clearly visible and indicates that the genus is distinct from, and relatively basal to, the only extant European cladonychiid genus, Holoscotolemon Roewer, 1915. Analysis of the claw morphology of extant cladonychiids, using evidence from ontogeny and outgroup comparison, suggests a transformation series in which the plesiomorphic condition (present in the eastern Nearctic genera Erebomaster Cope, 1872 and Theromaster Briggs, 1969) is a multi-pronged, narrowly forked claw with a long base, while the apomorphic condition (found in Holoscotolemon) is a bipronged, widely forked claw with a short base.
Der Weberknecht Gonyleptes nemastomoides Koch & Berendt, 1854 (Arachnida: Opiliones) aus dem Baltischen Bernstein (PalĂ€ogen: EozĂ€n) wird derzeit weder auf Gattungs- noch auf Familien-Ebene richtig zugeordnet. Er wird hiermit in die auch heute noch verbreitete Familie Cladonychiidae und die neue Gattung, Proholoscotolemon n. gen. versetzt. FĂŒr die Weberknecht-Familien Gonyleptidae und Phalangodidae gibt es somit keine fossilen Belege mehr. Obwohl das Typusexemplar von G. nemastomoides schlecht erhalten ist, ist die Form der diagnostisch wichtigen 4. Tarsalkrallen klar erkennbar. Sie zeigt an, dass die neue Gattung deutlich von der einzigen rezenten europĂ€ischen Cladonychiidae-Gattung Holoscotolemon Roewer, 1915 abweicht und im VerhĂ€ltnis hierzu ursprĂŒnglicher ist. Die Analyse der Krallen-Morphologie von lebenden Cladonychiidae, bei BerĂŒcksichtigung der Ontogenie und Vergleich mit AuĂengruppen, deutet auf eine Entwicklungs-Reihe hin, in welcher der plesiomorphe Zustand (vorhanden in den ost-nearktischen Gattungen Erebomaster Cope, 1872 und Theromaster Briggs, 1969) durch eine schmale, mehrfach gezackte und eng gegabelte Kralle mit einer langen Basis gekennzeichnet ist. Der apomorphe Zustand (vorhanden in Holoscotolemon) ist demgegenĂŒber eine zweizackige, breit gegabelte Kralle mit einer kurzen Basis.
doi:10.1002/mmng.200410005</a
A trigonotarbid arachnid from the early Devonian of Tredomen, Wales
A new trigonotarbid (Arachnida: Trigonotarbida) Arianrhoda bennetti gen. et sp. nov. is described from the
Lower Devonian (Lochkovian) of a quarry near Tredomen, Powys, mid Wales, UK. This relatively complete specimen
is the first record of a pre-Carboniferous arachnid from Wales, one of only a handful of early Devonian arachnids, and
the second oldest trigonotarbid recorded. Based on the rounded prosomal dorsal shield and the relatively narrow,
elongate opisthosoma we refer this new fossil to the family Anthracosironidae. A distinct flange-like ornament on the
leg 4 tibia in the new fossil is unique among trigonotarbids and is the primary autapomorphy for the new genus
New records of the great raft spider Dolomedes plantarius in Brandenburg (Araneae: Pisauridae)
The great raft spider, Dolomedes plantarius (Clerck, 1757), is a rare and endangered species in Germany and other European countries. Current data on its distribution and ecology are briefly reviewed. Five new (or overlooked) localities for this spider from the Spreewald-region of Brandenburg in eastern Germany are provided, together with an updated distribution map. One record, based on the authorsâ own collections, is described and figured in detail, with the egg-carrying female discovered in reeds at the edge of a fairly large body of open water. Both direct and indirect protective measures for the habitats of this species in the Spreewald-region are recommended
A FOSSIL WHIP-SCORPION (ARACHNIDA: THELYPHONIDA) FROM THE UPPER CARBONIFEROUS OF THE CARNIC ALPS (FRIULI, NE ITALY)
A new and well-preserved fossil whip scorpion (Arachnida: Uropygi: Thelyphonida) is described from the Late Carboniferous of the Carnic Alps, Friuli, Italy. It is referred to Parageralinura marsiglioi n. sp. The new specimen is the first Carboniferous arachnid to be described from mainland Italy and is possibly the youngest Palaeozoic thelyphonid
- âŠ