Two fragments of millipedes, referred to the genus Archispirostreptus, are reported from an archaeological site in the Tadrart Acacus region of southwestern Libya. Radiocarbon dating of the specimens shows that one of them dates to between ca. 9100 and 8800 years ago, and the other one between 6400 and 6300 years ago (calibrated dates). The site lies far from known present-day occurrences of spirostreptid millipedes, and the Libyan subfossils probably, like other isolated occurrences of Archispirostreptus species in the Sahara and the Middle East, represent geographical relicts of a former, continuous distribution. The millipedes were probably able to survive at the Libyan site during the early and middle Holocene periods thanks to the more humid conditions, and may descend from animals that initially colonised the area during the even more humid, and longer, last interglacial period.
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RBINS Staff Publications 2020
The ubiquitous sea cucumber Holothuria (Thymiosycia) arenicola Semper, 1868, externally characterized by a double row of dark blotches of various sizes on its dorsal body wall and a cryptic behaviour, is generally assumed to have a wide tropical distribution, although it has not been reported from the Eastern tlantic. Careful morphological examination, with emphasis on the ossicle assemblage, of type and non-type H. arenicola specimens sampled in the Indian, Pacific and tlantic Ocean, its subjective synonyms and species with a similar colouration and habit, revealed that H. arenicola is often confused with other species. This paper formally separates the different species in the H. arenicola complex, one of them being a species new to science: Holothuria (Thymiosycia) kerriensis sp. nov. dditionally, we describe two other species that are often confused with H. arenicola: Holothuria (Lessonothuria) gracilis Semper, 1868 and H. (Thymiosycia) strigosa Selenka, 1867. The H. arenicola complex per se is keyed-out, with the ossicle assemblage of the musculature being recognised as an important, previously largely neglected, guide. This contribution highlights the importance of building and curating well-maintaned natural history collections to understand biodiversity through time and space.
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RBINS Staff Publications 2024
