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28 August 2013 The Earliest Record of Terrestrial Animals in Gondwana: A Scorpion from the Famennian (Late Devonian) Witpoort Formation of South Africa
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Abstract

The new genus and species, Gondwanascorpio emzantsiensis, are described in Scorpiones incertae sedis on the basis of fragments from the Famennian (Late Devonian) Waterloo Farm locality near Grahamstown, Eastern Cape, South Africa. This finding adds to the sparse record of Late Devonian scorpion taxa and provides the first evidence of Palaeozoic scorpions from Gondwana. Material includes a complete chela with associated patella as well as a telson with associated metasomal segment V, resembling those of the Mesoscorpionina. This is the first record of a scorpion occurring at high latitudes. Its close resemblance to contemporary taxa from Laurasia and China is consistent with evidence from the type locality for increasingly uniform terrestrial ecosystems by the end of the Devonian, characterised by cosmopolitan plant genera such as the progymnosperm tree Archaeopteris. In part, this may reflect increasing proximity between Laurasia and Gondwana towards the end of the Devonian. These specimens also provide the earliest record of terrestrial animals in Gondwana.

INTRODUCTION

Modern scorpions are an abundant group generally occurring in tropical and warm temperate regions worldwide, although examples are known from cold high altitude environments in Patagonia. They are not known to occur naturally at latitudes higher than 50 degrees (Polis 1990). Scorpions are extremely conservative organisms that occur in the fossil record from the early Silurian period (Størmer 1977; Dunlop & Selden 2013) and are believed to have been an entirely terrestrial clade (e.g. Scholtz & Kamenz 2006; Dunlop et al. 2008; Kühl et al. 2012), with the exception of Devonian Waeringoscorpio Størmer, 1970 which may have been secondarily aquatic (Kühl et al. 2012).

Early scorpions were classically considered to have been aquatic and probably marine (e.g. Rolfe & Beckett 1984; Kjellesvig-Waering 1986; Polis 1990), all Silurian examples having been recovered from marginal marine lagoonal sediments (Jeram 1998). Terrestrialisation was believed to have occurred early in their history, probably during the Devonian period, with allegedly aquatic Proscorpiidae coexisting with terrestrial Mesoscorpionina and ‘palaeosterns’ until the early Carboniferous (Jeram 1998).

Evidence for terrestriality in mesoscorpions was provided by demonstration of booklungs in Pulmonoscorpius Jeram, 1994 from early Carboniferous strata of East Kirkton in Scotland (Jeram 1990, 1994). The presence of an oral tube (floored by the coxal apophyses) in structurally similar Pulmonoscorpius, Petaloscorpio Kjellesvig-Waering, 1986 and Hubeiscorpio Walossek, Li & Brauckmann, 1990 (Walossek et al. 1990) was considered indicative that the mesoscorpion clade that they comprise was terrestrial (Jeram 1998).

The view that basal scorpions were not terrestrial and that terrestrialisation occurred in scorpions independently of other Arachnida (Selden & Jeram 1989) carried the implication that the Araneae are not monophyletic (Scholtz & Kamenz 2006). This has been strongly refuted by Scholtz and Kamenz (2006) who argue that booklungs are an apomorphy of Araneae, that the Araneae are monophyletic and that they resulted from a single terrestrialisation event in their common stem lineage. This implies that all fossil scorpions were primarily terrestrial. Scholtz and Kamenz (2006) argue that several other arachnid characters such as trichobothria, slit-sense organs, endodermal malphigian tubules, and extra-intestinal digestion can be interpreted as apomorphic arachnid adaptations to land (Scholtz & Kamenz 2006).

Support for this view comes from the redescription of a number of apparently basal taxa. Dunlop et al. (2008) re-examined the oldest (Late Silurian) members of the Proscorpiidae, viz. Proscorpius Whitfield, 1885 (Whitfield 1885a , b ), Archaeophonus Kjellesvig-Waering, 1966 and Stoermeroscorpio Kjellesvig-Waering, 1986, and synonomised them under Proscorpius. They refuted evidence for gill openings and found no structural evidence to support an aquatic lifestyle. They assert that no definite evidence for internal gills or any unambiguously aquatic character has ever been unequivocally demonstrated in a fossil scorpion (Dunlop et al. 2008).

Palaeoscorpius devonicus Lehmann, 1944 from the Lower Devonian Hunsrück Slate Lagerstätte in Germany has also been re-investigated (Kühl et al. 2012). This key fossil was formerly interpreted as the most basal member of the Scorpiones and as one of the order's most likely candidates for an aquatic mode of life (Jeram 1998). New imagery was obtained using radiography, X-ray micro-tomography, and CT scanning techniques. Layered internal mesosomal organs were located and interpreted as probable book lungs (Kühl et al. 2012). Kühl et al. (2012) note that much of the argument for Palaeoscorpius Lehmann, 1944 being marine was based on the belief that the Hunsrück Slate was of deep marine origin. Conversely, recent studies of the palaeoenvironment suggest that the ‘Hunsrück Sea’ was part of an intrashelf basin close to the shore, into which terrestrial plants were periodically washed. Terrestrial material was likewise preserved in the lagoonal deposits that have yielded other early scorpions (Kühl et al. 2012). After reviewing all evidence Kühl et al. (2012) conclude that Palaeoscorpius was most likely to have been terrestrial. They also note that this provides strong evidence for arachnid monophyly and a single shared terrestrial arachnid ancestor. Highly unusual Lower Devonian Waeringoscorpio may have been secondarily aquatic as its unique filamentous external organs strongly resemble the tracheal gills of (secondarily) aquatic insects (Poschmann et al. 2008; Kühl et al. 2012).

Scorpion evolution is patchily represented in the fossil record due to the poor preservation potential of scorpions, particularly in terrestrial environments. Only 16 species, commonly represented by single specimens, of Silurian and Devonian scorpions were recognised in 15 genera by Jeram (1998). Of these, two Silurian genera and species have subsequently fallen away (Dunlop et al. 2008). All but one genus, Hubeiscorpio, have been recovered from European and North American strata (Sissom 1990), that at the time of their deposition formed a continuous land mass, Laurasia. Both Laurasia and China situated within tropical to subtropical latitudes during the Silurian and Devonian (Scotese & Mckerrow 1990; Mitchell et al. 2012).

Only two occurrences of scorpion fossils have been recorded from the Late Devonian (Jeram 1996, 1998). These are Petaloscorpio bureaui Kjellesvig-Waering, 1986 from the Frasnian Escuminac Formation of Canada (Jeram 1996) and Hubeiscorpio gracilitarsus Walossek, Li & Brauckmann, 1990 from the Frasnian of China (Walossek et al. 1990). Cladistic analysis of scorpions (Jeram 1998) places these two species as sister groups within the clade Mesoscorpionina, together with early Carboniferous Pulmonoscorpius (Acanthoscorpius Kjellesvig-Waering, 1986 having been subsequently removed from the Scorpiones (Legg et al. 2009)). The Mesoscorpionina form the sister group of late Carboniferous Palaeopisthacanthus Petrunkevitch, 1913, the earliest member of the crown group (Jeram 1998). Legg et al. (2009), however, suggest that mesoscorpions may be paraphyletic with regard to the crown group.

MATERIAL AND METHODS

New material consists of fragments recovered from the Witpoort Formation (Witteberg Group, Cape Supergroup) Waterloo Farm locality near Grahamstown, South Africa. This locality consists of black carbonaceous shale derived from anaerobic mud deposited in a back-barrier marginal marine lagoonal estuary (Gess & Hiller 1995a ). Organic remains accumulated in this setting include those of algae (Gess & Hiller 1995b ; Hiller & Gess 1996), terrestrial plants (Gess & Hiller 1995a; Anderson et al. 1995) and fish (Gess & Hiller 1995a ; Long et al. 1997; Gess 2001; Gess et al. 2006). Invertebrate remains include those of small smooth-shelled bivalves, ostracods, conchostacans, and a eurypterid (Gess & Hiller 1995a ). All fossil material consists of near two-dimensional compressions in which all original tissues have been replaced by secondary metamorphic mica. This has largely been altered to chlorite during uplift (Gess & Hiller 1995a ).

The Witpoort Formation strata at Waterloo Farm were deposited towards the end of the Famennian age of the Late Devonian period, approximately 360 million years ago. The Waterloo Farm estuary formed along the shoreline of the intracontinental Agulhas Sea, apparently within fifteen degrees of the south pole (Scotese & McKerrow 1990; Scotese & Barrett 1990; Mitchell et al. 2012) (Fig. 1).

Fig. 1.

Gondwanan reconstruction with position of the South Pole (star), main latitudes reconstructed for Late Devonian/Early Carboniferous (modified after Scotese & Barrett 1990), and the position of the Waterloo Farm (WF).

f01_373.jpg

Scorpion fragments, including a pedipalp chela articulating with a patella (Fig. 2A, B) and a telson attached to a metasomal segment V (Fig. 2C, D) have been recovered. The telson is slightly damaged where it has been compressed together with small plant fragments.

TAXONOMY

Order Scorpiones incertae sedis
Genus Gondwanascorpio gen. n.

  • Etymology: From Gondwana and Latin scorpio (scorpion). Masculine gender.

  • Type species: Gondwanascorpio emzantsiensis sp. n.

  • Diagnosis: The manus of the chela approximately equals the patella in length (character 11, Jeram 1998). Rami of the chela are very elongate, exceeding twice the length of the manus (character 13, Jeram 1998). Elongation of the manus and rami of the chela have been proposed as apomorphies helping to define the Mesoscorpionina together with crown group scorpions (Jeram 1998). Identification as a member of the Mesoscorpionina would, however, be incautious on the basis of only two characters. The gripping surfaces of the rami are crenulated, with crenulation peaks on the two rami arranged in an alternating pattern. There are 6 crenulations on the free ramus and probably 6 on the fixed ramus, though these are proximally more subdued. Notably the chela closely resembles that of Pulmonoscorpius, although the rami of the latter do not appear to be markedly crenulate. Comparison with Late Devonian genera is limited by lack of pedipalps in the type specimen Hubeiscorpio and their incomplete preservation in Petaloscorpio. The pedipalp chelae of Petaloscorpio are also elongate, although no further details have been described or illustrated. The telson of Gondwanascorpio resembles that of Pulmonoscorpius. Due to the fragmentary nature of the new material and paucity of knowledge of Palaeozoic scorpions the material is unidentifiable beyond Scorpiones incertae sedis. Close affinity to known Late Devonian and Early Carboniferous mesoscorpionine genera, particularly Pulmonoscorpius, is, however, probable.

Fig. 2.

Gondwanascorpio emzantsiensis gen. & sp. n.: (A, B) holotype AM5700, general appearance and details of pedipalp chela articulating with patella, (C, D) paratype AM5701, general appearance and details of telson and metasomal segment V. Abbreviations: ch — chela, fi.r. — fixed ramus, fr.r. — free ramus, ma — manus, pa — patella, m.V — metasomal segment V, p.f. — plant fragments, te — telson.

f02_373.jpg

Gondwanascorpio emzantsiensis sp. n. Fig. 2

  • Etymology: From genitive of isiXhosa umZantsi (south), which is sometimes used for South Africa.

  • Description:

  • Complete chela 25 mm long.

  • Holotype: AM7500 SOUTH AFRICA: Eastern Cape: Waterloo Farm, 33°19′23.97″S 26°32′13.05″E; Late Devonian, Famennian, Cape Supergroup, Witteberg Group, Witpoort Formation.

  • Paratype: AM7501, same locality and strata as holotype.

DISCUSSION

This represents the first record of a Palaeozoic scorpion from Gondwana. It is extremely unusual in that it has been recovered from rocks apparently deposited at a far higher latitude than that at which modern or fossil scorpions are known to have occurred. This may reflect amelioration of climatic gradients towards the end of the Devonian (Streel et al. 2000).

The presence of a scorpion in Gondwana, similar to Laurasian taxa, is consistent with growing evidence for globally comparable terrestrial ecosystems by the end of the Devonian. These were characterised by cosmopolitan plant genera such as the progymnosperm tree Archaeopteris, which has also been described from Waterloo Farm (Anderson et al. 1995). A breakdown in disparity between Gondwanan and Laurasian marginal marine ecosystems towards the end of the Devonian has previously been noted, possibly caused by increasing proximity of Laurasia to Gondwana (Young 1987).

Gondwanascorpio is the oldest known terrestrial animal from Gondwana. The only other putative terrestrial animal reported from the Devonian of Gondwana were tergites of Maldybulakia Tesakov & Alekseev, 1998 from Australia (Edgecombe 1998a , b ). Having at first been described from Kazakhstan as Lophodesmus, Maldybulakia was originally considered to most probably represent a type of myriapod (Tesakov & Alekseev 1992). It has subsequently been demonstrated that Maldybulakia most likely represents remains of an aquatic xiphosuran (Anderson et al. 1998; Edgecombe 2004).

The next oldest records of terrestrial animals from southern Africa are insects from the Early Permian Whitehill Formation (Ecca Group, Karoo Supergroup) (McLachlan & Anderson 1977) that was deposited approximately 90 million years later (Fildani et al. 2007). This remarkable gap in the regional fossil record is partially accounted for by a tectonically related 30 million year depositional hiatus, which began around 330 million years ago and was followed by a period of approximately 10 million years of deposition of the Dwyka Group (Karoo Supergroup) glacial diamictites. These resulted from southern Africa's passage over the South Pole during the Carboniferous and the consequent glaciation of most of Gondwana (Catuneanu et al. 2005).

ACKNOWLEDGEMENTS

I am grateful to Andrew Jeram for commenting on photos of the material as well as providing me with a set of his relevant reprints. Dr Jason Dunlop and two anonymous referees are thanked for their constructive comments. The Albany Museum (Grahamstown) provided office, lab and curatorial space. Prof. Bruce Rubidge is thanked for his unfailing support of this project. This research was supported by the National Research Foundation of South Africa and the Department of Science and Technology of South Africa. I dedicate this paper to my late father, Dr Friedrich Gess, who passed away on the 6th of August 2013 whilst I was revising the paper. He was an incredible role model as a scientist and a gentleman.

REFERENCES

  1. H.M. Anderson , N. Hiller & R.W. Gess 1995. Archaeopteris (Progymnospermopsida) from the Devonian of southern Africa. Botanical Journal of the Linnean Society 117: 305–320. Google Scholar
  2. L.I. Anderson , M. Poschmann & C. Brauckmann 1998. On the Emsian (Lower Devonian) arthropods of the Rhenish Slate Mountains: 2. The synziphosurine Willwerathia. Paläontologische Zeitschrift 72: 325–336. Google Scholar
  3. O. Catuneanu , H. Wopfner , P.G. Eriksson , B. Cairncross , B.S. Rubidge , R.M.H. Smith & P.J. Hancox 2005. The Karoo basins of south-central Africa. Journal of African Earth Sciences 43: 211–253. Google Scholar
  4. J.A. Dunlop & P.A. Selden 2013. Scorpion fragments from the Silurian of Powys, Wales. Arachnology 16(1): 27–32. Google Scholar
  5. J.A. Dunlop , O.E. Tetlie & L. Prendini 2008. Reinterpretation of the Silurian scorpion Proscorpius os- borni (Whitfield): integrating data from Palaeozoic and recent scorpions. Palaeontology 51 (2): 303–320. Google Scholar
  6. G.D. Edgecombe 1998a. Devonian terrestrial arthropods from Gondwana. Nature 394: 172–175. Google Scholar
  7. G.D. Edgecombe 1998b. Early myriapodous arthropods from Australia: Maldybulakia from the Devonian of New South Wales. Records of the Australian Museum 50 (3): 293–313. Google Scholar
  8. G.D. Edgecombe 2004. Morphological data, extant Myriopoda, and the myriopod stem group. Contributions to Zoology 73 (3): 207–241. Google Scholar
  9. A. Fildani , N.J. Drinkwater , A. Weislogel , T. Mchargue , D.M. Hodgson & S.S. Flint 2007. Age controls on the Tanqua and Laingsburg deep-water systems: New insights on the evolution and sedimentary fill of the Karoo Basin. Journal of Sedimentary Research 77: 901–908. Google Scholar
  10. R.W. Gess 2001. A new species of Diplacanthus from the Late Devonian (Famennian) of South Africa. Annales de Paléontologie 87: 49–60. Google Scholar
  11. R.W. Gess & N. Hiller 1995a. A preliminary catalogue of fossil algal, plant, arthropod, and fish remains from a Late Devonian black shale near Grahamstown, South Africa. Annals of the Cape Provincial Museums (Natural History) 19: 225–304. Google Scholar
  12. R.W. Gess & N. Hiller 1995b. Late Devonian charophytes from the Witteberg Group, South Africa. Review of Palaeobotany and Palynology 89: 417–428. Google Scholar
  13. R.W. Gess , M.I. Coates & B.S. Rubidge 2006. A lamprey from the Devonian period of South Africa. Nature 443: 981–984. Google Scholar
  14. N. Hiller & R.W. Gess 1996. Marine algal remains from the Upper Devonian of South Africa. Review of Palaeobotany and Palynology 91: 143–149. Google Scholar
  15. A.J. Jeram 1990. Book-lungs in a Lower Carboniferous scorpion. Nature 343: 360–361. Google Scholar
  16. A.J. Jeram 1994 (1993). Scorpions from the Visean of East Kirkton, West Lothian, Scotland, with a revision of the infraorder Mesoscorpionina. Transactions of the Royal Society of Edinburgh: Earth Sciences 84: 283–299. Google Scholar
  17. A.J. Jeram 1996. Chelicerata from the Escuminac Formation. In : H.-P. Schultze & R. Cloutier , eds, Devonian Fishes and Plants of Miguasha, Quebec, Canada. Munich: Dr Friedrich Pfeil, pp. 103–111. Google Scholar
  18. A.J Jeram 1998. Phylogeny, classification and evolution of Silurian and Devonian scorpions. In : P.A. Selden , ed., Proceedings of the 17th European Colloquium of Arachnology, Edinburgh, 1997. Burnham Beeches: The British Arachnological Society, pp. 17–31. Google Scholar
  19. E.N. Kjellesvig-Waering 1966. Silurian scorpions of New York. Journal of Paleontology 40: 359–375. Google Scholar
  20. E.N. Kjellesvig-Waering 1986. A restudy of the fossil Scorpionida of the world. Palaeontographica americana 55: 1–287. Google Scholar
  21. G. Kühl , A. Bergmann , J.A. Dunlop , R.J. Garwood & J. Rust 2012. Redescription and palaeobiology of Palaeoscorpius devonicus Lehmann, 1944 from the Lower Devonian Hunsrück Slate of Germany. Palaeontology 55: 775–787. Google Scholar
  22. D.A. Legg , S.J. Braddy & J.A. Dunlop 2009. The supposed scorpion Acanthoscorpio mucronatus Kjellesvig-Waering, recognized as a juvenile eurypterid and its implications for scorpion systematics. Progressive Palaeontology, Programme and Abstracts. Birmingham, UK: The Palaeontological Association & University of Birmingham, p. 19. Google Scholar
  23. W.H. Lehmann 1944. Palaeoscorpius devonicus n. g. n. sp., ein Skorpion aus dem rheinischen Unterdevon. Neues Jahrbuch für Paläontologie, Monatshefte B 7/9: 177–185. Google Scholar
  24. J.A. Long , M.E. Anderson , R.W. Gess & N. Hiller 1997. New placoderm fishes from the Late Devonian of South Africa. Journal of Vertebrate Palaeontology 17: 253–268. Google Scholar
  25. I.R. McLachlan & A.M. Anderson 1977. Fossil insect wings from the Early Permian White Band Formation, South Africa. Palaeontologia africana 20: 83–86. Google Scholar
  26. R.N. Mitchell , T.M. Kilian & D.A.D. Evans 2012. Supercontinent cycles and the calculation of palaeolongitude in deep time. Nature 482: 208–211. Google Scholar
  27. A.I. Petrunkevitch 1913. A monograph of the terrestrial Palaeozoic Arachnida of North America. Transactions of the Connecticut Academy of Arts and Sciences 18: 1–137. Google Scholar
  28. G.A. Polis 1990. Introduction. In : G.A. Polis , ed., The Biology of Scorpions. Stanford: Stanford University Press, pp. 1–8. Google Scholar
  29. M. Poschmann , J.A. Dunlop , C. Kamenz & G. Scholtz 2008. The Lower Devonian scorpion Waeringoscorpio and the respiratory nature of its filamentous structures, with the description of a new species from the Westerwald area, Germany. Paläontologische Zeitschrift 82: 418–436. Google Scholar
  30. W.D.I. Rolfe & C.M. Beckett 1984. Autecology of Silurian Xiphosurida, Scorpionida, and Phyllocarida. Special Papers in Palaeontology 32: 27–37. Google Scholar
  31. G. Scholtz & C. Kamenz 2006. The book lungs of Scorpiones and Tetrapulmonata (Chelicerata, Arachnida): Evidence for homology and a single terrestrialisation event of a common arachnid ancestor. Zoology 109: 2–13. Google Scholar
  32. C.R. Scotese & S.F. Barrett 1990. Gondwana's movement over the south Pole during the Palaeozoic: evidence from lithological indicators of climate. In : W.S. McKerrow & C.R. Scottese , eds, Palaeozoic palaeogeography and biogeography. Memoirs of the Geological Society of London 12: 75–86. Google Scholar
  33. C.R. Scotese & W.S. Mckerrow 1990. Revised world maps and introduction. In : W.S. McKerrow & C.R. Scotese , eds, Palaeozoic palaeogeography and biogeography. Memoirs of the Geological Society of London 12: 1–21. Google Scholar
  34. P.A. Selden & A.J. Jeram 1989. Palaeophysiology of terrestrialisation in Chelicerata. Transactions of the Royal Society of Edinburgh: Earth Sciences 80: 303–310. Google Scholar
  35. W.D. Sissom 1990. Systematics, Biogeography and Palaeontology. In : G.A. Polis , ed., The Biology of Scorpions. Stanford: Stanford University Press, pp. 64–160. Google Scholar
  36. L. Størmer 1970. Arthropods from the Lower Devonian (Lower Emsian) of Alken-an-der-Mosel, Germany. Part 1. Arachnida. Senchenbergiana Lethaia 51: 335–369. Google Scholar
  37. L. Størmer 1977. Arthropod invasion of land during Late Silurian and Devonian times. Science 197: 1362–1364. Google Scholar
  38. M. Streel , M.V. Caputo , S. Loboziak & G. Melo 2000. Late Frasnian–Famennian climates based on palynomorph analyses and the question of the Late Devonian glaciations. Earth Science Reviews 52: 121–173. Google Scholar
  39. A.S. Tesakov & A.S. Alekseev 1992. Myriapod-like arthropods from the Lower Devonian of central Kazakhstan. Paleontological Journal 26: 18–23. Google Scholar
  40. A.S. Tesakov & A.S. Alekseev 1998. Maldybulakia – new name for Lophodesmus Tesakov & Alekseev, 1992 (Arthropoda). Paleontological Journal 32: 49. Google Scholar
  41. D. Walossek , C.-S. Li & C. Brauckmann 1990. A scorpion from the Upper Devonian of Hubei Province, China (Arachnida, Scorpionida). Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 3: 169–180. Google Scholar
  42. R.P. Whitfield 1885a. An American Silurian scorpion (Palaeophonus osborni). Science 6: 87. Google Scholar
  43. R.P. Whitfield 1885b. On a fossil scorpion from the Silurian rocks of America. Bulletin of the American Museum of Natural History 6: 181–190. Google Scholar
  44. G.C. Young 1987. Devonian palaeontological data and the Armorica problem. Palaeogeography, Palaeoclimatology, Palaeoecology 60: 283–304. Google Scholar
and Robert W. Gess "The Earliest Record of Terrestrial Animals in Gondwana: A Scorpion from the Famennian (Late Devonian) Witpoort Formation of South Africa," African Invertebrates 54(2), (28 August 2013). https://doi.org/10.5733/afin.054.0206
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