Crossopriza lyoni Blackwall 1867
Creators: name: Huber, Bernhard A.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Crossopriza
Crossopriza lyoni

description: Crossopriza lyoni (Blackwall, 1867)
Tibiosa caracensis González-Sponga, 2006: 11–13; pl. 1, figs. 1–10; new synonymy. Tibiosa casanaimensis González-Sponga, 2006: 14–16; pl. 2, figs. 1–9; new synonymy. Tibiosa coreana González-Sponga, 2006: 17–19; pl. 3, figs. 1–9; new synonymy.
Tibiosa guayanesa González-Sponga, 2006: 20–22; pl. 4, figs. 1–9; new synonymy. Tibiosa moraensis González-Sponga, 2006: 23–25; pl. 5, figs. 1–9; new synonymy.
Justification of synonymies. Three lines of evidence strongly support the synonymies: the characters used by González- Sponga (2006) to diagnose the species, the biogeography of Crossopriza, and the microhabitats of the “new” species.
Characters. Male palps, male chelicerae, and the female epigynum are the most important characters to diagnose species in Pholcidae. Most of González-Sponga’s (2006) drawings of these characters are fairly good and clearly indicative of C. lyoni (for drawings, see Millot 1946, Beatty et al. 2008). However, in only one palp is the bulb in its natural position (plate 3); in the others it is slightly to strongly (plates 1, 4) rotated which produces significantly different views. By manipulating a bulb under a dissecting microscope, all these views can easily be reproduced. All drawings of male chelicerae clearly show the two pairs of very distinctive apophyses that characterize C. lyoni but do not occur in this conformation in any other described or undescribed species seen by the author (see below).
Two of the epigyna in González-Sponga (2006, plates 1, 5) are fairly good representations of what is seen in adult C. lyoni females. Plate 2 probably shows a male genital area. The anterior structures shown are light spots in the otherwise black area in front of the epigastric furrow; they occur in variable shape and size in juveniles and adults of both sexes. The posterior structure probably represents the small brown plate in front of the male gonopore. The “epigynum” in plate 4 is probably from a juvenile specimen. In plate 3, figs. 8 and 9 are almost certainly from Artema atlanta. Both the round abdomen and the distinctive epigynum strongly hint at that species.
Most drawings of palpal endites are appropriate and show the usual variation (both true and artificial) seen in these—in pholcids otherwise taxonomically barely informative—structures. On plate 2, the endites are probably covered by a piece of dirt or an extrusion of internal fluids.
Carapace shape is rarely a distinctive character within pholcid genera, and all the variation shown in González- Sponga’s (2006) drawings can easily be attributed to small differences in the angle of view and to slight deformations of the soft lateral margins. Differences in the angle of view also explain the minimal differences shown in the positions of the eyes.
The sternum in Crossopriza lyoni has a straight posterior border between the joints of the fourth leg coxae. The lateral extensions shown by González-Sponga (2006) are in fact extensions of the carapace that reach ventrally on both sides of the petiole and almost contact the sternum. The median extension is in fact an unpaired sclerite on the petiolus. The borders of all these sclerites are often poorly visible due to underlying patterns of dark pigment in the soft tissue directly under the cuticle.
Finally, size measures are a difficult character to separate species. Except for one species, all male tibia 1 measures (10.1–15.8 mm) fall within the range of C. lyoni. The only exception (table 2) is clearly an error: in this male, leg 1 has the shortest tibia of all legs, while in fact it should have the longest (like the female and like all other “species”). In at least two cases (tables 2, 3, male legs 1) leg length calculations are wrong, further eroding confidence in these measurements.
Biogeography. Crossopriza lyoni is a cosmotropical spider that has been collected in many countries including North, Central, and South America. I have seen specimens from many countries, including Argentina, Paraguay, Brazil, Nicaragua, USA (Huber et al. 1999), Venezuela (listed in Colmenares-García 2008), and Haiti (unpublished). Except for C. lyoni, Crossopriza is restricted to Africa north of the Equator and the Arabian Peninsula. I have seen congeneric species (described and undescribed) from Guinea, Ivory Coast, Burkina Faso, Ghana, Equatorial Guinea, Chad, Congo DR, Sudan, Ethiopia, Yemen, and Oman. A taxonomic revision of this material is in preparation.
Microhabitat. Four of González-Sponga’s (2006) “new species” where collected in human buildings. One was additionally found under waist, one on the walls of a dry ravine. For the fifth species, no data on microhabitat are given. Human constructions and their surroundings are the typical habitat of C. lyoni.
description: Published as part of Huber, Bernhard A., 2009, Four new generic and 14 new specific synonymies in Pholcidae, and transfer of Pholcoides Roewer to Filistatidae (Araneae), pp. 64-68 in Zootaxa 1970 on page 65, DOI: 10.5281/zenodo.185015