Fossil Record 15 (2) 2012, 91–101 / DOI 10.1002/mmng.201200007 An enigmatic spiny harvestman from Baltic amber Jason A. Dunlop*,1, Christian Bartel2 and Plamen G. Mitov3 1 Museum fr Naturkunde Berlin, Leibniz-Institut fr Evolutions- und Biodiversittsforschung, Invalidenstraße 43, 10115 Berlin, Germany. E-mail: [email protected] 2 Birkholzer Allee 97, 16356 Ahrensfelde, Germany. E-mail: [email protected] 3 Department of Zoology and Anthropology, Faculty of Biology, University of Sofia, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria. E-mail: [email protected] Abstract Received 4 November 2011 A new harvestman (Arachnida: Opiliones) from Baltic amber (Palaeogene: Eocene; ca. Accepted 13 January 2012 44–49 Ma) is described as Piankhi steineri n. gen., n. sp. This enigmatic fossil ex- Published 3 August 2012 presses long, slender pedipalps without a tarsal claw, which is characteristic for the suborder Dyspnoi. The chelicerae are notably enlarged and the dorsal body surface is formed from a carapace with a separate prosomatic tergite (metapeltidium), plus a large opisthosomal scute (or scutum parvum). However these characters, combined with the distinctly spiny limbs and further rows of spines across the fossil’s opisthosoma, have no parallel among the modern dyspnoid harvestmen that we are aware of. The fossil Key Words resolves features reminiscent of modern members of the dyspnoid families Ceratolas- matidae, Nipponopsalididae, Ischyropsalididae and Sabaconidae, but does not show un- Arachnida equivocal apomorphies of any one particular family. We must entertain the possibility Dyspnoi that this is an extinct body plan from the Eocene of north-central Europe, and we ten- Eocene tatively refer the fossil to a new genus in an unresolved position among the Ischyropsa- Opiliones lidoidea (Dyspnoi). An amorphous triangular structure behind the anal region is as- systematics sumed to be faecal matter, rather than part of the original anatomy. Introduction our attention for having long, spiny legs, elongate and slender pedipalps, and multiple rows of short spines Harvestman (Arachnida: Opiliones) are a diverse group across the body (Figs 1–4). Compared to previous de- of arthropods in modern terrestrial ecosystems, with scriptions, this is evidently something new for the amber nearly 6,500 living species described thus far (Kury fauna. Further study revealed that it preserves an unu- 2000; data as of March 2011). By contrast only thirty sual combination of characters, raising questions about valid fossil species of harvestman are known, albeit with its familial affinities. It is formally described as a new a record going back some 410 million years to the Early genus and species below. Devonian. A general review of the harvestman fossil record can be found in Dunlop (2007). The most pro- ductive locality for fossils of these arachnids is Baltic amber, which dates from the Eocene (ca. 44–49 Ma) of Materials and methods north-central Europe. Four suborders of Opiliones are The type and only known specimen originates from the private collec- conventionally recognised: Cyphophthalmi, Eupnoi, tion of Dr Michael Steiner (Free University Berlin) and has now been Dyspnoi and Laniatores. All have now been recorded formally deposited in the amber collections of the Museum fr Natur- from Baltic amber (cf. Koch & Berendt 1854; Menge kunde Berlin (MfN) under the repository number MB.A.1878 (for 1854; Roewer 1939; Dunlop & Mammitzsch 2010; Dun- Museum Berlin Arthropoda). The specimen was originally obtained lop & Mitov 2011). Further comments on this amber over ten years ago from Polish traders and may originate from the fauna, and partial revisions of some species, have also Polish coast of the Baltic Sea (M. Steiner, pers. comm. 2011). The fossil was photographed using a Leica stereomicroscope running the been published by Stare˛ga (1976, 2002), Ubick & Dun- software package Leica Application Suite. Stacks of in most cases ca. lop (2005) and Dunlop (2006). Here, we describe a new 30 images were assembled into a single final picture using the soft- specimen from Baltic amber which immediately caught ware package Auto Montage. Brightness, contrast, etc. were adjusted * Corresponding author # 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 92 Dunlop,J.A.etal.:Spinyamberharvestman Figure 1. Piankhi steineri n. gen, n. sp. Overview of the complete animal (holotype and only known specimen: MB.A.1878) from Eocene Baltic amber (ca. 44–49 Ma). A. Dorsal view; B. Dorso-lateral view. Scale bar equals 2 mm. manually in Adobe Photoshop. Drawings were prepared using a Leica tion terminology follow Martens (1969a, fig. 10; 1972, fig. 2; 1978), MZ12 stereomicroscope with a camera lucida attachment. The amber and Shultz & Pinto-da-Rocha (2007, fig. 2.4). fossil was compared to descriptions of living species in the literature Baltic amber is conventionally dated to an Eocene (Lutetian) age of – initially Roewer (1923) then also Sato & Suzuki (1939), Sˇilhavy´ about 44–49 Ma. Details of the geological setting, other faunal ele- (1956), Martens & Suzuki (1966), Gruber (1970, 1978), Ljovushkin ments and the presumably warm palaeoenvironment can be found in (1971), Suzuki (1974), Shear (1975, 1986, 2010a) and Martens (1978, Weitschat & Wichard (2010) and references therein. 1983, 1989) – and to extant, alcohol-preserved material in the Mu- seum fr Naturkunde Berlin and in the P. Mitov collection (PM). All measurements are in mm. Systematic paleontology Comparative material studied and photographed: Hesperonemasto- ma modestum (Banks, 1894) (Figs 5A, B). – 1 male (body length 1.17); USA, California, Monterey County, 28.X.1982, leg. Roy John- Order Opiliones Sundevall, 1833 son, Jr., det. J. C. Cokendolpher, (PM); Taracus birsteini Ljovuschkin, Suborder Dyspnoi Hansen & Sørensen, 1904 1971 (Figs 5C–G). – 1 male (body length 4.2), 1 female (body length Remarks. The position of this new fossil is challenging. 4.6); Russia, Maritime Province, NW part of Vladivostok City, cata- The long legs (Figs 1, 4A) evidently exclude the subor- combs, 21.VIII.1998, coll. Yu. M. Marusik, det. A. N. Chemeris, (PM). Note that we accept here the conclusions of Giribet et al. der Cyphophthalmi, while the fact that the pedipalps (2010) and Shear (2010b) in placing Hesperonemastoma Gruber, are not raptorial precludes an assignment to Laniatores. 1970 in Sabaconidae rather than Ceratolasmatidae. Scutum combina- This leaves Eupnoi and Dyspnoi. The shape of the pedi- museum-fossilrecord.wiley-vch.de # 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Fossil Record 15 (2) 2012, 91–101 93 Figure 2. Piankhi steineri n. gen, n. sp. Body and proximal limb region. A. Dorsal view; B. Dorso-lateral view. Scale bar equals 1 mm. # 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim museum-fossilrecord.wiley-vch.de 94 Dunlop,J.A.etal.:Spinyamberharvestman museum-fossilrecord.wiley-vch.de # 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Fossil Record 15 (2) 2012, 91–101 95 palp (Figs 3C, 4C) clearly points towards Dyspnoi; par- (Gruber 2007). However, unlike our fossil there are no ticularly the fact the tarsus is the shortest article and robust spines on the ocularium, on the appendages or that it lacks an obvious tarsal claw. By contrast, in Eu- on the body in general. The chelicerae of nipponopsali- pnoi the tarsus of the pedipalp is usually the longest dids are also proportionally much larger that those of article and ends in a single, curved and clearly visible the fossil, and further differences are elucidated below. claw. However, the new fossil, with its spiny legs and Superficially similar to Nipponopsalididae is the fa- body, does not appear to fall neatly into any of the mily Ischyropsalididae although this group apparently known dyspnoid families (as reviewed by Gruber belongs in the second superfamily, Ischyropsalidoidea. 2007). This resemblance is thus considered convergent (Gruber 2007) and Ischyropsalididae is currently represented by a single genus, Ischyropsalis C. L. Koch, 1839, found Superfamily ?Ischyropsalidoidea Simon, 1879 in Central Europe and the Pyrenees, including the Car- Remarks. Dyspnoi is traditionally divided into two super- pathians, the northern Iberian Peninsula and the Italian families: Troguloidea and Ischyropsalidoidea. Cladistic Peninsula. A putative record of Ischyropsalis hellwigi studies (Shultz & Regier 2001; Giribet et al. 2002, (Panzer, 1794) in Turkey (Central Anatolia region) (see 2010) have largely supported this basic scheme; with Kurt et al. 2008) requires confirmation whereby materi- Giribet et al. (2010) estimating a split between these al merits revision. These are also distinctive harvestmen groups as far back as the late Carboniferous. The trogu- with long and spiny chelicerae. Ischyropsalis hellwigi is loid families Trogulidae, Dicranolasmatidae and Ne- known to be a specialist predator on gastropods and the mastomatidae all have highly characteristic body shapes especially enlarged and powerful mouthparts are used (see also figures in Martens 1978) which differ sub- here to crack snail shells (Martens 1965; Nyffeler & stantially from the new amber fossil. For example di- Symondson 2001). The diets of other Ischyropsalis spe- cranolasmatids have eyes borne on a forward-projecting cies are not well known. As with nipponopsalidids, ex- ‘hood’ while in trogulids the eyes are at the very tip of tant ischyropsalidids have not been recorded with all the prosoma close to the basis of the two hood arms. In the characters seen in our fossil; namely stout spines on all of these three families the carapace region merges the ocularium, legs and body. What is worth mention- smoothly into the dorsal opisthosoma forming the so- ing here is that Martens’ (1978, p. 186) diagnosis of called scutum magnum. By contrast, in the new fossil the ischyropsalidids includes the fact that – as in the the carapace appears to be differentiated from the amber specimen – the abdominal tergites can be fused opisthosoma and is not fused to the succeeding ter- into a scutum parvum. The large chelicerae of the fossil gite(s). In fact the carapace of the fossil even shows a are also worth reiterating.