A review of fossil scorpion higher systematics.

Scorpions (Arachnida: Scorpiones) are a diverse and widespread arachnid order with a rich and deep fossil record. Here we review the, sometimes complex, historical development of fossil scorpion higher classification. We present a chronological account of family and genus names, together with an overview of higher taxa as potential clade names.

Early Pennsylvanian Lagerstätte reveals a diverse ecosystem on a subhumid, alluvial fan.

Much of what we know about terrestrial life during the Carboniferous Period comes from Middle Pennsylvanian (~315-307 Mya) Coal Measures deposited in low-lying wetland environments. We know relatively little about terrestrial ecosystems from the Early Pennsylvanian, which was a critical interval for the diversification of insects, arachnids, tetrapods, and seed plants. Here we report a diverse Early Pennsylvanian trace and body fossil Lagerstätte (~320-318 Mya) from the Wamsutta Formation of eastern North America, distinct from coal-bearing deposits, preserved in clastic substrates within basin margin conglomerates.

Nuttalliellidae in Burmese amber: implications for tick evolution.

Ticks are composed of 3 extant families (Argasidae, Ixodidae and Nuttalliellidae) and 2 extinct families (Deinocrotonidae and Khimairidae). The Nuttalliellidae possess one extant species () limited to the Afrotropic region. A basal relationship to the hard and soft tick families and its limited distribution suggested an origin for ticks in the Afrotropics.

An unexpected diversity of Cyphophthalmi (Arachnida: Opiliones) in Upper Cretaceous Burmese amber.

Ten new Cyphophthalmi specimens (Arachnida: Opiliones) from the Upper Cretaceous (Lower Cenomanian) Burmese amber of northern Myanmar are described. Seven of these are placed in Stylocellidae, the predominant extant family found today in Southeast Asia. Sirocellus iunctus gen.

Hard ticks in Burmese amber with Australasian affinities.

Three examples of metastriate hard ticks (Ixodida: Ixodidae) with apparent affinities to modern Australasian genera are described from the mid-Cretaceous (ca. 100 Ma) Burmese amber of Myanmar. Two nymphs of sp.

A remarkable assemblage of ticks from mid-Cretaceous Burmese amber.

Four fossil ticks (Arachnida: Parasitiformes: Ixodida) are described from mid-Cretaceous (ca. 100 Ma) Burmese amber of Myanmar. sp.

Harvestmen (Arachnida: Opiliones) in Eocene Rovno amber (Ukraine).

Six species of harvestman (Arachnida: Opiliones) are documented from the Eocene Rovno amber in Ukraine. From the suborder Eupnoi we record Caddo dentipalpus (C. L.

The complete mitochondrial genome of the pentastomid (Pentastomida) from reindeer () in Northern Norway.

Here, we present the first complete mitochondrial genome of the pentastomid collected from the nasal passages of a reindeer () in Norway. The full length mitochondrial genome of , which measures 14,789 bp in length, contains 13 protein-coding genes, 2 ribosomal RNA genes and 22 transfer RNA genes. A clear A + T bias is observed in the mitogenome of with an overall base composition of 32.

Evolution: A Breath of Fresh Air for Eurypterids.

Eurypterids - Paleozoic 'sea scorpions' that could grow several meters long - were thought to have been aquatic. Computer tomography reveals that respiratory organs of a new fossil eurypterid resemble arachnid book lungs, supporting the hypothesis that eurypterids - and perhaps arachnid ancestors - were amphibious.

Trilobite compound eyes with crystalline cones and rhabdoms show mandibulate affinities.

Most knowledge about the structure, function, and evolution of early compound eyes is based on investigations in trilobites. However, these studies dealt mainly with the cuticular lenses and little was known about internal anatomy. Only recently some data on crystalline cones and retinula cells were reported for a Cambrian trilobite species.

Miniaturisation in Chelicerata.

Arachnids and their relatives (Chelicerata) range in body length from tens of centimetres in horseshoe crabs down to little more than 80-200 μm in several groups of mites. Spiders (Araneae) show the widest range within a given Bauplan - the largest species being ca. 270 times longer than the smallest - making them excellent models to investigate scaling effects.

Microbial decay analysis challenges interpretation of putative organ systems in Cambrian fuxianhuiids.

The Chengjiang fossil (Cambrian Stage 3) from Yunnan, southern China is renowned for its soft-tissue preservation. Accordingly structures in fuxianhuiids, radiodontans and great appendage arthropods have been interpreted as the nervous and cardiovascular systems, including brains, hearts and blood vessels. That such delicate organ systems survive the fossilization process seems remarkable; given that this mode of preservation involves major taphonomic changes, such as flattening, microbial degradation, chemical alteration and replacement.

Haemaphysalis cretacea a nymph of a new species of hard tick in Burmese amber.

The first fossil potentially assignable to the extant hard tick genus Haemaphysalis CL Koch (1844) (Ixodida: Ixodidae) is described from the Late Cretaceous (ca. 99 Ma) Burmese amber of Myanmar. Haemaphysalis (Alloceraea) cretacea sp.

Cretaceous arachnid Chimerarachne yingi gen. et sp. nov. illuminates spider origins.

Spiders (Araneae) are a hugely successful lineage with a long history. Details of their origins remain obscure, with little knowledge of their stem group and few insights into the sequence of character acquisition during spider evolution. Here, we describe Chimerarachne yingi gen.

Terrestrial invertebrates in the Rhynie chert ecosystem.

The Early Devonian Rhynie and Windyfield cherts remain a key locality for understanding early life and ecology on land. They host the oldest unequivocal nematode worm (Nematoda), which may also offer the earliest evidence for herbivory via plant parasitism. The trigonotarbids (Arachnida: Trigonotarbida) preserve the oldest book lungs and were probably predators that practiced liquid feeding.

Amblyomma birmitum a new species of hard tick in Burmese amber.

Amblyomma birmitum sp. nov. is formally described as a new record from 99 Ma old Burmese amber from Myanmar.

The complete mitochondrial genome of the pentastomid (Pentastomida) from the Democratic Republic of Congo.

We present the first complete mitochondrial genome of the pentastomid (Arthropoda: Pentastomida) collected from the lungs of a rhinoceros viper () in the Democratic Republic of Congo. The full length mitochondrial genome of , which measures 16,073 bp in length, contains 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. A clear A + T bias is observed in the mitogenome of with an overall base composition of 34.

Microtomography of the Baltic amber tick Ixodes succineus reveals affinities with the modern Asian disease vector Ixodes ovatus.

Background: Fossil ticks are extremely rare and Ixodes succineus Weidner, 1964 from Eocene (ca. 44-49 Ma) Baltic amber is one of the oldest examples of a living hard tick genus (Ixodida: Ixodidae). Previous work suggested it was most closely related to the modern and widespread European sheep tick Ixodes ricinus (Linneaus, 1758).

Segmentation and tagmosis in Chelicerata.

Patterns of segmentation and tagmosis are reviewed for Chelicerata. Depending on the outgroup, chelicerate origins are either among taxa with an anterior tagma of six somites, or taxa in which the appendages of somite I became increasingly raptorial. All Chelicerata have appendage I as a chelate or clasp-knife chelicera.

Permian scorpions from the Petrified Forest of Chemnitz, Germany.

Background: Paleozoic scorpions (Arachnida: Scorpiones) have been widely documented from the Carboniferous Period; which hosts a remarkable assemblage of more than sixty species including both putative stem- and crown-group fossils. By contrast the succeeding Permian Period is almost completely devoid of records, which are currently restricted to a trace fossil from the early Permian of New Mexico, USA and some limb fragments from the late Permian of the Vologda Region, Russia.

Results: ?Opsieobuthus tungeri sp.

Almost a spider: a 305-million-year-old fossil arachnid and spider origins.

Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We describe a new fossil arachnid, Idmonarachne brasierigen.

Penis morphology in a Burmese amber harvestman.

A unique specimen of the fossil harvestman Halitherses grimaldii Giribet and Dunlop, 2005 (Arachnida: Opiliones) from the Cretaceous (ca. 99 Ma) Burmese amber of Myanmar reveals a fully extended penis. This is the first record of a male copulatory organ of this nature preserved in amber and is of special importance due to the age of the deposit.