The largest fossil of the segmented spider Parvithele muelleri Wunderlich, 2017 (Mesothelae: Parvithelidae) from Cretaceous Burmese amber

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  The largest fossil of the segmented spider Parvithele muelleri Wunderlich, 2017 (Mesothelae: Parvithelidae) from Cretaceous Burmese amber Abstract A new specimen of the fossil spider Parvithele muelleri Wunderlich, 2017 (Araneae: Mesothelae) is described from the mid-Cretaceous (ca. 99 Ma) Burmese amber of Myanmar. Like the original holotype, the new specimen is a mature male, which clearly preserves a series of tibial macrospines, similar to the condition in the extant genus Liphistius Schiødte, 1849. Given that the single extant mesothele family, Liphistiidae, is predicted to have radiated ca. 39–58 million years ago, the occurrence of somewhat modern-looking male pedipalp spination in older fossil mesotheles is of considerable interest. The new specimen also shows spinnerets in a relatively posterior position, although variability observed in extant species suggests that this trait may be of limited systematic value. Of particular note is the presence of a large and well-dev...

Phrynus abstrusus : a new troglophilous whip spider (Amblypygi, Phrynidae) from southern Texas (American Museum novitates no. 4050)

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Phrynus abstrusus : a new troglophilous whip spider (Amblypygi, Phrynidae) from southern Texas (American Museum novitates no. 4050)

Abstract

The arachnid order Amblypygi Thorell, 1883, currently comprises 299 described species in 18 genera and five families, a surprisingly low diversity compared to other globally distributed arachnid orders. The genus Phrynus Lamarck, 1801, the most speciose genus of the Neotropical family Phrynidae Blanchard, 1852, is one of several amblypygid genera that contain much undescribed diversity. For example, its type species, Phrynus operculatus Pocock, 1902, allegedly distributed from southern Texas to Guatemala, appears to represent a complex of more range-restricted cryptic species. Existing records suggest a disjunction in the distribution of P. operculatus, with the Texan population separated from Mexican populations by considerable distance and a potential barrier of unsuitable desert habitat. The recent collection and examination of new material from the Big Bend area of southern Texas revealed that the Texan population is not conspecific with typical P. operculatus material from Mexico and Central America. It differs from the latter in being almost entirely depigmented and is the third troglomorphic species of Phrynus. The morphology and habitat of this unusual troglophilous species, named Phrynus abstrusus, sp. nov., are described herein.

Cazzaniga, Nicolas, Prendini, Lorenzo. (2026). Phrynus abstrusus: A new troglophilous whip spider (Amblypygi, Phrynidae) from southern Texas (American Museum Novitates No. 4050). American Museum of Natural History. Retrieved from https://digitallibrary.amnh.org/items/112d8b7c-04ba-4474-aeb6-943782ffd690