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Simplified representations of Carboniferous whip spiders from the literature. a-d From Mazon Creek, USA. a Sorellophrynus carbonarius, UMMP 7220, holotype (based on Petrunkevitch 1913: combined from text-figs. 32, 33). b Thelyphrynus elongatus, UMMP 7222, holotype (based on Petrunkevitch 1913: combined from textfigs. 27, 28). c, d Weygoldtina scudderi. c USNM 37969, holotype (based on Petrunkevitch 1913: combined from text-figs. 29, 30). d USNM 37964 (based on Petrunkevitch 1913: text-fig. 31). e-i Brit-
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Whip spiders (Amblypygi), as their name suggests, resemble spiders (Araneae) in some aspects, but differ from them by their heart-shaped (prosomal) dorsal shield, their prominent grasping pedipalps, and their subsequent elongate pair of feeler appendages. The oldest possible occurrences of whip spiders, represented by cuticle fragments, date back t...
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... the Mazon Creek Lagerstätte. The specimen is the holotype of the species Weygoldtina scudderi (originally Graephonus scudderi or Graephonus carbonarius as the first name was mostly overlooked; see Dunlop 2018). The specimen appears quite complete, including shield, trunk, parts of pedipalps and locomotory appendages. (6) Specimen USNM 37964 ( Fig. 2d; Petrunkevitch 1913: text- fig. 31, plate V, fig. 29) was considered to represent an additional specimen of Weygoldtina ...
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... holotype of the species Weygoldtina scudderi (originally Graephonus scudderi or Graephonus carbonarius as the first name was mostly overlooked; see Dunlop 2018). The specimen appears quite complete, including shield, trunk, parts of pedipalps and locomotory appendages. (6) Specimen USNM 37964 ( Fig. 2d; Petrunkevitch 1913: text- fig. 31, plate V, fig. 29) was considered to represent an additional specimen of Weygoldtina ...
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... specimen mainly preserves the trunk and part of the locomotory appendages. Still, based on the available characters, Dunlop (2018) tentatively accepted the interpretation of Petrunkevitch (1913). (7) Specimen BMNH (British Museum of Natural History, NHM London) In31260 (Fig. 2e) comes from the British Coal Measures (Carboniferous) and has been interpreted as a representative of Weygoldtina anglica (originally Graephonus anglicus; also depicted in Pocock 1911: plate I, fig. 4). The specimen has a well-preserved shield and trunk ( Dunlop et al. 2007a: fig. 4c, d). Also parts of the posterior locomotory ...
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... are preserved close to the trunk. The figure in Dunlop et al. (2007a) states two different repository numbers, BMNH In 31260 for their fig. 4c, and BMNH In 31620 for their fig. 4d. In the text, both figures are referred to as BMNH In 31260. It seems, therefore, that these are part and counterpart of one specimen. (8) Specimen BMNH In 22836 (Fig. 2f) is an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5e). (9) Specimen BMNH I 13872 (Fig. 2g) is also an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. ...
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... In the text, both figures are referred to as BMNH In 31260. It seems, therefore, that these are part and counterpart of one specimen. (8) Specimen BMNH In 22836 (Fig. 2f) is an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5e). (9) Specimen BMNH I 13872 (Fig. 2g) is also an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5c). (10) Specimen BMNH I 7892 (Fig. 2h) is also an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: ...
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... from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5e). (9) Specimen BMNH I 13872 (Fig. 2g) is also an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5c). (10) Specimen BMNH I 7892 (Fig. 2h) is also an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5a). (11) Specimen BMNH I 7905 (Fig. 2i) is, also, an isolated trunk, with some remains of the locomotory appendages, from the British Coal Measures. It was interpreted as a ...
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... from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5c). (10) Specimen BMNH I 7892 (Fig. 2h) is also an isolated trunk from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5a). (11) Specimen BMNH I 7905 (Fig. 2i) is, also, an isolated trunk, with some remains of the locomotory appendages, from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5b). (12) Specimen MM (Manchester Museum) LL 11000 ( Fig. 2j) comes from the Writhlington Geological Nature Reserve (Carboniferous). The ...
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... of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5a). (11) Specimen BMNH I 7905 (Fig. 2i) is, also, an isolated trunk, with some remains of the locomotory appendages, from the British Coal Measures. It was interpreted as a representative of Weygoldtina anglica by Dunlop et al. (2007a: fig. 5b). (12) Specimen MM (Manchester Museum) LL 11000 ( Fig. 2j) comes from the Writhlington Geological Nature Reserve (Carboniferous). The specimen has a preserved trunk and parts of the locomotory appendages (Dunlop 1994: figs. 3, 4). While the specimen is incomplete, Dunlop (1994) argued that the specimen is a representative of Sorellophrynus carbonarius; this was further supported by Dunlop ...
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... one spine in rather lateral orientation apparent. Pedipalps appear almost parallel to each other, only a slight inclination is apparent. More proximal parts of all locomotory appendages preserved. (15) Specimen BMNH In 31234 (Figs. 6, 7) is a representative of Weygoldtina anglica. It is preserved as part and counterpart ( Dunlop et al. 2007a: figs. 1c, d, 2c, d; also depicted in Pocock 1911: plate I: fig. 4c). The specimen is very well preserved, even exhibiting the feeler-type appendage. The specimen has been threedimensionally reconstructed based on µCT scanning ( Garwood et al. 2017). Also light-based documentation reveals numerous details of the shield shape and the appendages. The ...
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... the shield and the right pedipalp. The pedipalps appear to be highly foldable and have a horizontal plane of action (Fig. 16c). In ventral view (Fig. 17a, b), the subdivision of the trunk is well apparent. (33) Specimen Tad 456 (Fig. 18) is the holotype and only known specimen of the species Paracharonopsis cambayensis (Engel and Grimaldi 2014: figs. 1, ...
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... (1971). The specimen is preserved in Miocene Mexican Chiapas amber (15-20 mya). Dunlop and Mru- Simplified representations of whip spiders from the Crato Formation, Britopygus weygoldti. a SMNS 64332 (based on Dunlop and Martill 2001). b SMNS 66123 (based on Dunlop and Barov 2005) (2015) provided a better documentation of the specimen (Fig. 2), but concluded that the species is a nomen dubium, as the specimen is rather incomplete. It mostly provides some details of the pedipalp and few aspects of the proximal regions of the locomotory appendages. (35) Specimen Do 1703-K-1 (Fig. 19b) is the holotype of Phrynus resinae (originally Tarantula resinae; Scha- waller 1979). The ...
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... some details of the pedipalp and few aspects of the proximal regions of the locomotory appendages. (35) Specimen Do 1703-K-1 (Fig. 19b) is the holotype of Phrynus resinae (originally Tarantula resinae; Scha- waller 1979). The specimen is preserved in Dominican Miocene amber. The specimen is accessible in dorsal view ( Fig. 1) and ventral view (Fig. 2). Also many small details are accessible, including details of the pedipalp (Fig. 3) and of the locomotory appendages (Fig. 5). (36) Specimen Do-3357 (Fig. 19c) is another specimen of Phrynus resinae (Schawaller 1982). It is also preserved in Dominican Miocene amber. The specimen is well accessible in dorsal view (Fig. 7); also some ...
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... specimen is well accessible in dorsal view (Fig. 7); also some aspects of the inner skeleton are accessible (Fig. 8). (37) Specimen Do-1370 (Fig. 19d) is another specimen of Phrynus resinae (Schawaller 1982). It is also preserved in Dominican Miocene amber. A habitus image of the specimen was not provided, only details of the feeler appendages (Fig. 2). (38) Specimen Do-3000 (Fig. 20a) is another specimen of Phrynus resinae (Schawaller 1982). It is also pre- Fig. 14 Simplified representations of whip spiders from amber from Myanmar. a, b Kronocharon prendinii. a JZC Bu150 (based on Engel and Grimaldi 2014). b Unnamed specimen (based on Selden and Ren 2017). c Unnamed specimen (based ...
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... dorsal view (Fig. 7); also some aspects of the inner skeleton are accessible (Fig. 8). (37) Specimen Do-1370 (Fig. 19d) is another specimen of Phrynus resinae (Schawaller 1982). It is also preserved in Dominican Miocene amber. A habitus image of the specimen was not provided, only details of the feeler appendages (Fig. 2). (38) Specimen Do-3000 (Fig. 20a) is another specimen of Phrynus resinae (Schawaller 1982). It is also pre- Fig. 14 Simplified representations of whip spiders from amber from Myanmar. a, b Kronocharon prendinii. a JZC Bu150 (based on Engel and Grimaldi 2014). b Unnamed specimen (based on Selden and Ren 2017). c Unnamed specimen (based on Xia et al. 2015). d Kronocharon ...
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... g Unnamed specimen 11095 (based on Gröhn 2015) Fig. 15 Simplified representation of a whip spider from amber from Myanmar, Burmacharon dunlopi, NIGP173207 (based on Hu et al. 2020) served in Dominican Miocene amber. The specimen is well accessible in dorsal view (Fig. 8); also details of the pedipalps are accessible (Fig. 4). (39) A specimen (Fig. 20b) is an exuvium of the group Phrynus (Poinar 1992: 221, fig. 114). It is also preserved in Dominican Miocene amber. The specimen is well accessible in dorsal view (221, fig. 114). (40) Another specimen (Fig. 20c) is also a representative of Phrynus (Poinar and Poinar 1999: 78, between pp. 110/111, fig. 78), preserved in Dominican amber. ...
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... 2015) Fig. 15 Simplified representation of a whip spider from amber from Myanmar, Burmacharon dunlopi, NIGP173207 (based on Hu et al. 2020) served in Dominican Miocene amber. The specimen is well accessible in dorsal view (Fig. 8); also details of the pedipalps are accessible (Fig. 4). (39) A specimen (Fig. 20b) is an exuvium of the group Phrynus (Poinar 1992: 221, fig. 114). It is also preserved in Dominican Miocene amber. The specimen is well accessible in dorsal view (221, fig. 114). (40) Another specimen (Fig. 20c) is also a representative of Phrynus (Poinar and Poinar 1999: 78, between pp. 110/111, fig. 78), preserved in Dominican amber. The image provided is rather small and does not provide many ...
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... amber. The specimen is well accessible in dorsal view (Fig. 8); also details of the pedipalps are accessible (Fig. 4). (39) A specimen (Fig. 20b) is an exuvium of the group Phrynus (Poinar 1992: 221, fig. 114). It is also preserved in Dominican Miocene amber. The specimen is well accessible in dorsal view (221, fig. 114). (40) Another specimen (Fig. 20c) is also a representative of Phrynus (Poinar and Poinar 1999: 78, between pp. 110/111, fig. 78), preserved in Dominican amber. The image provided is rather small and does not provide many details. We still try to provide here an interpretation of the principle morphology. Still, we feel uncertain in some aspects and do not consider the ...
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... A specimen (Fig. 20d) is beautifully preserved in Dominican Miocene amber (Wunderlich 2004: 594, photo 695). The specimen is incredibly complete, including the feeler-like appendages. (42) A specimen is the holotype of Phrynus mexicanus ( Fig. 20e; originally Phrynus mexicana, see discussion in Dunlop and Mrugalla 2015) described by Poinar and Brown (2004). ...
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... A specimen (Fig. 20d) is beautifully preserved in Dominican Miocene amber (Wunderlich 2004: 594, photo 695). The specimen is incredibly complete, including the feeler-like appendages. (42) A specimen is the holotype of Phrynus mexicanus ( Fig. 20e; originally Phrynus mexicana, see discussion in Dunlop and Mrugalla 2015) described by Poinar and Brown (2004). The fossil is preserved in Miocene Chiapas amber (Mexico). An overview was provided as a photograph (594, photo 696), details were provided as drawings, including central body ( Fig. 1), pedipalps (Figs. 2-7), eye region ...
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... of Phrynus mexicanus ( Fig. 20e; originally Phrynus mexicana, see discussion in Dunlop and Mrugalla 2015) described by Poinar and Brown (2004). The fossil is preserved in Miocene Chiapas amber (Mexico). An overview was provided as a photograph (594, photo 696), details were provided as drawings, including central body ( Fig. 1), pedipalps (Figs. 2-7), eye region (Fig. 6), chelicerae (Fig. 7), and distal region of leg (Fig. ...
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... the length-width ratios of trunk vs shield reveals a distinct pattern (Fig. 21). Carboniferous specimens plot further to the upper right. Modern specimens occupy a larger range, but plot more to the lower left with one exception, namely Paracharon caecus, which plots in the upper right area. Specimens from the Cretaceous and Eocene/Miocene plot in between. There is a large overlap of the groups, not a distinct ...
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... also other ratios reveals a similar pattern (Fig. 22). For the ratios of the pedipalp (pedipalp/shield, pedipalp/trunk), the weight point of the group of Carboniferous specimens forms one extreme, the weight point of the group of modern specimens the other one. The weight points of the groups of Cretaceous specimens and Eocene/ Miocene specimens are ...
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... and Mrugalla 2015). b-d Dominican amber, Phrynus resinae. b Do 1703-K-1 (based on Schawaller 1979). c Do-3357 (based on Schawaller 1982). d Do-1370(based on Schawaller 1982 ventral spines. Yet, for the extant species Paracharon caecus, these terms appear inappropriate due to the nearly vertical orientation of the pedipalps ( Garwood et al. 2017: fig. 2). The terms can be well correlated when comparing the pedipalps to those of other modern forms. Yet, this would mean to provide an upward frame of comparison, i.e. interpret a possibly more plesiomorphic morphology (as seen in P. caecus) in the light of a possibly more derived one (as in representatives of Euamblypygi, the group ...
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... when comparing the pedipalps to those of other modern forms. Yet, this would mean to provide an upward frame of comparison, i.e. interpret a possibly more plesiomorphic morphology (as seen in P. caecus) in the light of a possibly more derived one (as in representatives of Euamblypygi, the group including all extant species of Amblypygi besides Fig. 20 Simplified representations of whip spiders from Miocene ambers. a-d Dominican amber. a Phrynus resinae, Do-3000 (based on Schawaller 1982). b Specimen of Phrynus (based on Poinar 1992). c Specimen of Phrynus (based on Poinar and Poinar 1999). d Specimen based on Wunderlich (2004). e Mexican amber, Phrynus mexicanus (based on Poinar and ...
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... representations of whip spiders from Miocene ambers. a-d Dominican amber. a Phrynus resinae, Do-3000 (based on Schawaller 1982). b Specimen of Phrynus (based on Poinar 1992). c Specimen of Phrynus (based on Poinar and Poinar 1999). d Specimen based on Wunderlich (2004). e Mexican amber, Phrynus mexicanus (based on Poinar and Brown 2004) Fig. 21 Scatter plot of lengthwidth ratio of trunk vs lengthwidth ratio of shield of whip spiders; specimens from similar time slices depicted with same symbols possibly one species, see "Discussion" below and Garwood et al. 2017: fig. ...
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... spine orientation of the pedipalps of Weygoldtina anglica seems to differ from that in pedipalps of the modern species of Paracharon caecus. The spines in P. caecus appear to be almost parallel, slightly tilted outwards. In the pedipalps of W. anglica, the angle between the spines Fig. 22 Range of different ratios for whip spiders from different time slices. C Carboniferous, Ec Eocene, ex extant, K Cretaceous, Mc Miocene appears to be larger, at least 90°, i.e. the spines appear further oriented outwards. This indicates that W. anglica used its pedipalps not exactly in the same way as the modern P. caecus. The ...
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... the projection as a true apomorphy. The argument is, yet, not as strong as suggested. The shield of whip scorpions (Thelyphonida) could well also be understood as drawn out anteriorly. Also the feature appears not as unique as suggested, as also some modern species of Euamblypygi show this type of morphology (e.g. Teruel and Questel 2015: fig. ...
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... Especially there is clear indication that it is strongly foldable and acting mostly in the horizontal plane. These characters clearly indicate a closer relationship, or even an ingroup position within Euamblypygi for P. cambayensis, especially as also modern representatives of Euamblypygi have a protruding shield (e.g. Teruel and Questel 2015: fig. ...
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... a weak shift is observable concerning overall shape of the shield and the trunk (Fig. 21). Yet, it is well apparent that in the Carboniferous, the shields were, at least on average, more elongate. This appears to account also for the trunk. In the Cretaceous, there is a slight shift towards broader forms, further continued into even broader forms in the modern fauna, with the exception of Paracharon caecus with a ...
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... ratios of appendage lengths vs length of shield or trunk show a clearer signal (Fig. 22), most likely due to the stronger variability in width, especially in the case of the trunk. It is well apparent that the relative length of pedipalp and locomotory appendages was rather short in the Carboniferous, increased in the Cretaceous, and became highly variable, but on average longer in the modern fauna. Again the ...
Citations
... nov. Paracharonopsis cambayensis Engel andGrimaldi, 2014, the Early Eocene amber fossil from Gujarat, India, is hereby removed from Paracharontidae for the following reasons: As noted by Haug and Haug (2021), the pedipalp orientation of P. cambayensis appears to be more horizontal than vertical (Engel and Grimaldi, 2014: 5, fig. 1) like Euamblypygi and unlike Paracharontidae. Furthermore, several other characters suggest that P. cambayensis is more closely related to Euamblypygi than to Paracharontidae. ...
... Unlike Weygoldt (1996), Garwood et al., (2017) scored Paracharon for the presence of lateral ocelli. Subsequently, Haug and Haug (2021) criticized some interpretations of Garwood et al. (2017), suggesting that other whip spider taxa (e.g., Charinus desirade Teruel and Questel, 2015) and arachnid orders (e.g., Thelyphonida) exhibit a projection of the anterior carapace margin similar to that observed in Paracharontidae, a putative synapomorphy of Paleoamblypygi, and further suggesting that the pedipalps of Paracharonopsis appear almost horizontally rather than vertically oriented. ...
... Another controversial character (Haug and Haug, 2021) is the projection of the anterior carapace margin, proposed as a synapomorphy for Paleoamblypygi by Weygoldt (1996) and Garwood et al. (2017). Although superficially similar in shape among some Euamblypygi, e.g., Charinus desidare and Sarax seychellarum (Kraepelin, 1898), the anterior carapace projection does not cover the cheliceral bases in these taxa, unlike in Graeophonus, Paracharon, and Jorottui. ...
The ancient, enigmatic whip spider family Paracharontidae Weygoldt, 1996, representing the basalmost lineage of the arachnid order Amblypygi Thorell, 1883, is revised. The monotypic West African genus Paracharon Hansen, 1921, from Guinea Bissau, is redescribed, based on a reexamina-tion and reinterpretation of the newly designated lectotype. A new troglobitic whip spider, Jorottui ipuanai, gen. et sp. nov., is described from a cave system in the upper basin of the Camarones River in the La Guajira Department of northeastern Colombia. This new taxon is the second extant representative of Paracharontidae and the first outside Africa. It is unambiguously assigned to the family based on several characters shared with Paracharon caecus Hansen, 1921, notably a projection of the anterior carapace margin, the tritosternum not projecting anteriorly, similar pedipalp spination, a reduced number of trichobothria on the tibia of leg IV, and cushionlike female gonopods. A detailed examination confirmed the absence of ocelli in both genera and the presence of three (Paracharon) vs. four (Jorottui, gen. nov.) prolateral teeth on the basal segment of the chelicera, the dorsalmost tooth bicuspid in both genera. The male gonopods of Paracharontidae are described for the first time. Paracharonopsis cambayensis Engel and Grimaldi, 2014, is removed from Paracharontidae and placed incertae sedis in Euamblypygi Weygoldt, 1996; amended, comparative diagnoses are presented for
... Not fictitious at all, amblypygids (sometimes called whip spiders because of their elongate antenniform legs) are nocturnal predators that can be found throughout the tropics and subtropics, with some species also inhabiting more temperate and desert zones (Weygoldt 2000;Chapin and Hebets 2016). These remarkable animals have changed little over evolutionary time, with complete fossils dating back to the Carboniferous (300 mya) and fossil fragments dating back 385 mya, to the Devonian (Dunlop 2010;Haug and Haug 2021). The order is monophyletic (Ban et al. 2022) and not particularly diverse in comparison to other arachnid orders, with just 255 currently described species compared to the spider Order Araneae with more than 50,300 currently described species (World Spider Catalog accessed 8 September 2022). ...
From both comparative biology and translational research perspectives, there is escalating interest in understanding how animals navigate their environments. Considerable work is being directed towards understanding the sensory transduction and neural processing of environmental stimuli that guide animals to, for example, food and shelter. While much has been learned about the spatial orientation behavior, sensory cues, and neurophysiology of champion navigators such as bees and ants, many other, often overlooked animal species possess extraordinary sensory and spatial capabilities that can broaden our understanding of the behavioral and neural mechanisms of animal navigation. For example, arachnids are predators that often return to retreats after hunting excursions. Many of these arachnid central-place foragers are large and highly conducive to scientific investigation. In this review we highlight research on three orders within the Class Arachnida: Amblypygi (whip spiders), Araneae (spiders), and Scorpiones (scorpions). For each, we describe (I) their natural history and spatial navigation, (II) how they sense the world, (III) what information they use to navigate, and (IV) how they process information for navigation. We discuss similarities and differences among the groups and highlight potential avenues for future research.
... Whip spiders (Amblypygi) are terrestrial euchelicerates consisting of ca. 220 species (Weygoldt 2000a(Weygoldt , 2002aHarvey 2003;Miranda et al. 2016Miranda et al. , 2018aHaug & Haug 2021). Amblypygids are tropical and subtropical organisms (Harvey 2003) that have dorso-ventrally flattened exoskeletons and inhabit gaps between rocks and gaps in trees (Weygoldt 2000a(Weygoldt , 2002a. ...
... Further, coxa of antenniform legs are not aligned with coxae of adjacent appendages. This species may therefore be the only extant example of a whip spider with nearly complete horizontally articulated pedipalps (Garwood et al. 2017;Haug & Haug 2021). Such a morphology was more common in some extinct groups ( fig. 3 in Garwood et al. 2017;Haug & Haug 2021). ...
... This species may therefore be the only extant example of a whip spider with nearly complete horizontally articulated pedipalps (Garwood et al. 2017;Haug & Haug 2021). Such a morphology was more common in some extinct groups ( fig. 3 in Garwood et al. 2017;Haug & Haug 2021). Thus, kinematic analyses of the joints of extant taxa exhibiting this trochanteral organization could enhance our understanding of joint morpho-functionality across amblypygid groups. ...
Amblypygi are tropical and subtropical ambush predators that use elongated, raptorial pedipalps for different activities. Although pedipalps use for predation and courtship has been explored in videography in-vivo analyses, kinematic ex-vivo examination of these appendages has not been conducted yet. Here, we rectify this lack of data by using micro-CT scans to 3D-kinematically model the appendage morphology and the range of motion (ROM) of the joints for Damon medius and Heterophrynus elaphus. We illustrate the successful application of this technique to terrestrial euarthropods in determining the maximum ROM values for each pedipalp joint. We also note that in life, these values would be lower due to motion restricting structures like tendons, arthrodial membranes and muscles. We further compare our maximum values obtained here with data from video-based motion analyses. The ROM of each joint shows the greatest flexibility in the femur-tibia joint (140–150°), the lowest in the basitarsus-claw joint (35–40°). ROM in the tibia-basitarsus joint is markedly distinct (D. medius: 44°; H. elaphus: 105°). This disparity reflects how H. elaphus uses the joint in the capture basket, while D. medius uses femur-tibia joint to form the capture basket. We further illustrate notable vertical motion of H. elaphus´ pedipalp compared to D. medius. This difference reflects the retro-ventral trochanter apophysis of H. elaphus. Our study opens the possibility to further whip spiders kinematic understanding. Examination of other taxa using this approach will result in a more comprehensive understanding of the ecological significance and ethological implications of this unique arachnid group.
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This is a supplement to the Burmese (Myanmar) amber checklist and bibliography covering taxa described or recorded during 2021, plus a few earlier records that were missed previously. Up to the end of 2021, 2,198 species were recorded from Kachin amber of which 337 were named in 2021. Five species were named or recorded from older Hkamti amber.
Like other arthropods, whip spiders of the arachnid order Amblypygi Thorell, 1883 protect themselves against external environmental influences. In addition to the epicuticle, the outermost layer of the exoskeleton, an additional cement layer, i.e., the cerotegument, is deposited as superhydrophic globules over certain body parts in this taxon. Due to the high level of interspecific variation, the cerotegument structure and the morphology of its associated gland openings, have been suggested to be informative for whip spider systematics and taxonomy. The first comparative study of the cerotegument is presented herein, based on a survey across four families, 16 genera and 62 species of Euamblypygi Weygoldt, 1996, the suborder comprising all extant whip spiders except the rare monotypic family Paracharontidae Weygoldt, 1996. Results confirmed that the morphology of the colloidal particles and their assembly on globules differ considerably among taxa, but that the level of variation differs among lineages. Interspecific variation in cerotegument ultrastructure was highest among species of Neoamblypygi Weygoldt, 1996, making it an informative character in this clade. Evolutionary trends and interspecific variation in the structure of the amblypygid cerotegument are briefly discussed. This article is protected by copyright. All rights reserved.
This taxonomic list is a supplement to Ross (2021). It includes taxa described or recorded from the beginning of January 2021 up to the end of May 2021, plus 3 species that were named in 2020 which were missed.
