Difference between revisions of "Afrarchaea"

Revision as of 16:22, 8 January 2018

Taxonavigation

Ordo: Araneae
Familia: Archaeidae

Name

Afrarchaea Forster & Platnick, 1984 – Wikispecies link – Pensoft Profile

• Afrarchaea Forster & Platnick, 1984: 24.

Type species

Archaea godfreyi Hewitt, 1919: 196, figs 1–2 (by original designation).

Diagnosis

Distinguished from all extant genera by the presence of a prominent keel on the FSGP (see fig. 58 of Forster and Platnick (1984)^[1], fig. 3 of Lotz (2006)^[2], and figs 1c–d and 6b–c of Lotz (1996)^[3]). The keel likely has been lost in A. royalensis and A. ngomensis given the central phylogenetic placement of these two species (Fig. 1).

Description

See Forster and Platnick (1984)^[1] for description.

Included species

12 described species, A. cornutus (Lotz, 2003), A. ansieae Lotz, 2015, A. bergae Lotz, 1996, A. entabeniensis Lotz, 2003, A. fernkloofensis Lotz, 1996, A. godfreyi (Hewitt, 1919), A. haddadi Lotz, 2006, A. harveyi Lotz, 2003, A. kranskopensis Lotz, 1996, A. lawrencei Lotz, 1996, A. ngomensis Lotz, 1996, A. royalensis Lotz, 2006, A. woodae Lotz, 2006. Two species originally described as Afrarchaea have been transferred: A. fisheri Lotz, 2003 and A. mahariraensis Lotz, 2003, both to Eriauchenus (new combinations).

Distribution

South Africa.

Discussion

Phylogenetic analysis based on molecular data recovered a monophylectic Afrarchaea with strong branch support (Wood et al. 2015^[4]). This research supports the transfer of A. cornutus from Eriauchenius to Afrarchaea and the transfer of E. mahariraensis from Afrarchaea to Eriauchenius (Fig. 1). Furthermore, females of A. cornutus have a FSGP keel typical of Afrarchaea (see fig. 3 of Lotz 2006^[2]) and females of E. mahariraensis do not (Fig. 15B–C).
Regarding Afrarchaea distribution, Legendre (1970)^[5] reported on a male and female specimen (not examined for this study) collected at Manjakatompo, Madagascar, which he identified as Afrarchaea godfreyi. However, Legendre noted that these specimens were different from A. godfreyi in some details (i.e., the absence of prominent cephalic spines and the absence of abdominal sclerotization). These differences suggest that these specimens are not A. godfreyi. Unfortunately, in the CAS collections only a single juvenile specimen has been collected from Manjakatompo. This specimen also has reduced spines on the cephalon (only one rudimentary spine is present), which is again suggestive that this specimen is not A. godfreyi. Furthermore, many Eriauchenius species endemic to Madagascar have the short fat “neck” typical of most Afrarchaea (other than A. cornutus and A. ansieae) and also have reduced spination on the cephalon. The species E. fisheri, E. goodmani sp. n., E. harveyi sp. n., E. mahariraensis, E. ratsirarsoni, E. sama sp. n., and E. wunderlichi sp. n. all superfically resemble Afrarchaea in terms of carapace shape (Figs 9A, 10A, 11A, 12A, 15A). E. mahariraensis and E. fisheri were originally described as Afrarchaea based solely on carapace shape (Lotz 2003^[6]). Current research on archaeids shows that carapace shape has evolved in parallel, with similar morphs evolving repeatedly (Wood 2017^[7]; Wood et al. 2015^[4]; Wood et al. 2007^[8]), suggesting that carapace shape is not a good diagnostic trait for these genera. Phylogenetic analysis (Wood et al. 2015^[4]) and morphological examination of numerous African and Madagascan specimens suggests instead that the African and Madagascan species are short-range endemics that are restricted to either southern Africa or Madagascar, but not both (Fig. 1). Furthermore, after over 10 years of extensive collecting in Madagascar by CAS researchers, specimens of Afrarchaea godfreyi have never been found. For these reasons we propose that the distribution of Afrarchaea godfreyi be restricted to South Africa until evidence suggests otherwise.

Taxon Treatment

• Wood, H; Scharff, N; 2017: A review of the Madagascan pelican spiders of the genera Eriauchenius O. Pickard-Cambridge, 1881 and Madagascarchaea gen. n. (Araneae, Archaeidae) ZooKeys, (727): 1-96. doi

Images

Figure 1. Total evidence phylogeny from Bayesian analysis of molecular and morphological data, from Wood et al. (2015)[4]. Outgroups not shown and with the morphospecies names changed to the new species names from the current study. Posterior probabilities are as follows, greater than or equal to: (*) 0.90; (**) 0.95; (***) 0.99.  Figure 9. Eriauchenius fisheri (Lotz, 2003). A male (CASENT9018939) habitus, lateral view, image reversed B–C female (holotype, CASENT9012340) internal genitalia B dorsal view C anterior view D–L male pedipalpal bulbs (CASENT9018939) D–F, L right bulb, image reversed G–K left bulb D, G, J prolateral view E, H, K ventral view F, I retrolateral view K close-up, ventral view. Scale bars: 1 mm (A); 0.25 mm (B, D).  Figure 10. Eriauchenius goodmani sp. n. A male (holotype, Field Museum) habitus, lateral view B–C female (Field Museum) genitalia B dorsal view C ventral view D–F male left pedipalpal bulb (holotype, Field Museum) D prolateral view E ventral view F retrolateral view. Scale bars: 1 mm (A); 0.25 mm (B, D).  Figure 11. Eriauchenius harveyi sp. n. A male (holotype, CASENT9012110) habitus, lateral view, image reversed B–C female (CASENT9012342) genitalia B dorsal view C ventral view D–K male pedipalpal bulbs (CASENT9012109) D–F right bulb, image reversed G–K left bulb D, G, J prolateral view E, H, K ventral view F, I retrolateral view L male (CASENT9012109), arrow showing the long cheliceral seta that projects perpendicularly from the chelieral cuticle, lateral view. Scale bars: 1 mm (A); 0.25 mm (B, D).  Figure 12. Eriauchenius wunderlichi sp. n. A female (CASENT9062648) habitus, lateral view, image reversed B–C female (CASENT9062648) genitalia B dorsal view, arrow showing the large bulge on the posterior bar C ventral view D–F male left pedipalpal bulb (holotype, CASENT9062702) D prolateral view E ventral view F retrolateral view. Scale bars: 1 mm (A); 0.25 mm (B, D).  Figure 15. Eriauchenius mahariraensis (Lotz, 2003). A male (USNMENT01377173) habitus, lateral view, image reversed B–C female (holotype, MCZ) internal genitalia B dorsal view C anterior view, arrow showing the small sclerotized piece next to the poreplates D–K male pedipalpal bulbs (USNMENT01377173) D–F right bulb, image reversed G–L left bulb: D, G, J prolateral view E, H, K ventral view F, I, L retrolateral view. Scale bars: 1 mm (A); 0.125 mm (B, D)..

Other References

1. ↑ ^{1.0 1.1} Forster R, Platnick N (1984) A review of the archaeid spiders and their relatives, with notes on the limits of the superfamily Palpimanoidea (Arachnida, Araneae). Bulletin of the American Museum of Natural History 178: 1–106.
2. ↑ ^{2.0 2.1} Lotz L (2006) Afrotropical Archaeidae: 3. The female of Eriauchenius cornutus and new species of Afrarchaea (Arachnida: Araneae) from South Africa. Navorsinge van die Nasionale Museum Bloemfontein 22: 113–126.
3. ↑ Lotz L (1996) Afrotropical Archaeidae (Araneae): 1. New species of Afrarchaea with notes on Afrarchaea godfreyi (Hewitt, 1919). Navorsinge van die Nasionale Museum Bloemfontein 12: 141–160.
4. ↑ ^{4.0 4.1 4.2 4.3} Wood H, Gillespie R, Griswold C, Wainwright P (2015) Why is Madagascar special? The extraordinarily slow evolution of pelican spiders (Araneae, Archaeidae). Evolution 69: 462–481. https://doi.org/10.1111/evo.12578
5. ↑ Legendre R (1970) Arachnides-Araignées-Archaeidae. Faune de Madagascar 32: 1–50.
6. ↑ Lotz L (2003) Afrotropical Archaeidae: 2. New species of genera Archaea and Afrarchaea (Arachnida: Araneae). Navorsinge van die Nasionale Museum Bloemfontein 19: 221–240.
7. ↑ Wood H (2017) Integrating fossil and extant lineages: an examination of morphological space through time (Araneae: Archaeidae). The Journal of Arachnology 45: 20–29. https://doi.org/10.1636/JoA-S-16-039.1
8. ↑ Wood H, Griswold C, Spicer G (2007) Phylogenetic relationships within an endemic group of Malagasy ‘assassin spiders’ (Araneae, Archaeidae): ancestral character reconstruction, convergent evolution and biogeography. Molecular Phylogenetics and Evolution 45: 612–619. https://doi.org/10.1016/j.ympev.2007.07.012