Zoosyst. Evol. 88 (1) 2012, 19–24 / DOI 10.1002/zoos.201200003 Nomenclatural notes on the eurypterid family Carcinosomatidae Jason A. Dunlop*,1 and James C. Lamsdell2 1 Museum fçr Naturkunde Berlin, Leibniz-Institut fçr Evolutions- und Biodiversitåtsforschung an der Humboldt-Universitåt zu Berlin, Invalidenstraße 43, 10115 Berlin, Germany 2 Department of Geology and Paleontological Institute, University of Kansas, 1475 Jayhawk Boulevard, Lawrence, KS 66045, U.S.A. Abstract Received 19 August 2011 The genus level systematics of the eurypterid family Carcinosomatidae (Chelicerata Accepted 6 September 2011 Eurypterida) is briefly reviewed, with particular reference to some nomenclatural prob- Published 16 March 2012 lems associated with homonyms and their replacement names. Eusarcus scorpionis Grote & Pitt, 1875 is the type species of both Eusarcana Strand, 1942 and Paracarci- Key Words nosoma Caster & Kjellesvig-Waering, 1964. Although Strand’s name has been comple- tely overlooked in the eurypterid literature, it remains the oldest available (and valid) Eurypterida name associated with Eusarcus scorpionis. It should be noted that Strand replaced a Fossil homonym under circumstances when this was not really necessary, but the Principle of Nomenclature Priority means that we are forced to reclassify three Paracarcinosoma species under his Homonyms genus name as Eusarcana scorpionis (Grote & Pitt, 1875), Eusarcana acrocephala Embrik Strand (Semper, 1898) and Eusarcana obesa (Woodward, 1868); all comb. nov. Introduction Systematics The eurypterid family Carcinosomatidae (Chelicerata: Family Carcinosomatidae Størmer, 1934 Eurypterida) includes a number of quite large and 1934 Carsinosomidae Størmer, p. 104. highly distinctive fossil arthropods. Its constituent spe- 1955 Carcinosomatidae: Størmer, p. 35 [nom. correct.] cies are characterised by spiny forelegs, large paddles, a broad and rounded preabdomen, and a slender postab- Remarks. The family group name was introduced, as domen ending in a curved telson. In this sense, they Carcinosomidae, by Størmer (1934) for the genera Car- appear quite scorpion-like (Fig. 1) and were presumably cinosoma Claypole, 1890 [including in this sense Eu- one of the groups which contributed to the eurypterids’ sarcus Grote & Pitt 1875; see below], Mixopterus Rue- common name of ‘sea scorpions’. Within Carcinosoma- demann, 1921, Echinognathus Walcott, 1882 and tidae, a number of genera have been proposed; some of Megalograptus Miller, 1874. The latter three genera them unfortunately representing preoccupied names were subsequently transferred to their own families, (see below). This has led to a degree of nomenclatural whereby family authorship should effectively be cred- confusion and inconsistencies in the literature. In parti- ited to Caster & Kjellesvig-Waering in Størmer (1955). cular, we were recently made aware of the fact that one In detail, the new family names were first mentioned in of the oldest published names, Eusarcus scorpionis the Treatise on Invertebrate Paleontology, albeit draw- Grote & Pitt, 1875, is ostensibly the type species of ing on a manuscript by Kenneth Caster and Erik Kjel- two separate genera: the widely overlooked Eusarcana lesvig-Waering which was supposedly in press at the Strand, 1942 and the more familiar Paracarcinosoma time of writing, but in fact came out much later as Cas- Caster & Kjellesvig-Waering, 1964. Here, we attempt ter & Kjellesvig-Waering (1964). Thus in 1955 Mixop- to resolve this issue as part of a brief review the basic terus was assigned to Mixopteridae; Echinognathus and systematic structure of the family Carcinosomatidae. Megalograptus to Megalograptidae. For completeness, the species composition of all four currently recognised carcinosomatid genera is listed be- low. * Corresponding author, e-mail: [email protected] # 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 20 Dunlop, J. A. & Lamsdell, J. C.: Nomenclatural notes on Carcinosomatidae Figure 1. Specimen (non-type) of Eusarcus (now Eusarcana) scorpionis (Grote & Pitt, 1875) from the Silurian ‘Bertie Waterlime’ of New York, USA; courtesy of the American Museum of Natural History, New York (image taken by Steve Thurston). Carcinosoma Claypole, 1890 Type species. Eurysoma newlini Claypole, 1890a [= C. ingens Clay- pole, 1894]. 1890a Eurysoma Claypole, p. 259 [preoccupied by Eurysoma Dejean, 1831 (Coleoptera)] Other included species. C. harleyi Kjellesvig-Waering, 1961b, C. liber- 1890b Carcinosoma Claypole, p. 400 [replacement name] tyi Copeland & Bolton, 1960, ?C. punctatum (Salter in Huxley & museum-zoosyst.evol.wiley-vch.de # 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Zoosyst. Evol. 88 (1) 2012, 19–24 21 Salter, 1859); C. scorpioides (Woodward, 1868) [= Pterygotus rani- sumably mentioned the Eusarcus problem, and also re- ceps Woodward, 1868], C. scoticus (Laurie, 1899), ?C. spiniferum ceived confirmation from Strand that Carcinosoma was Kjellesvig-Waering & Heubusch, 1962. not preoccupied and still available. For reasons best known to himself, Strand subsequently proposed – Eocarcinosoma Caster & Kjellesvig-Waering, 1964 without comment – a replacement name for Eusarcus; namely Eusarcana Strand, 1942. Why he felt the urge 1964 Eocarcinosoma Caster & Kjellesvig-Waering, p. 314. to replace a name which had already been dealt with Type and only species. Eocarcinosoma batrachophthalmus Caster & satisfactorily by Størmer’s nomenclatural act is hard to Kjellesvig-Waering, 1964. fathom, but contemporary critiques of Strand’s ap- proach to systematics (Mortensen 1929; Richter 1929) Eusarcana Strand, 1942 and his apparent desire to have as many taxon names associated with his own authorship as possible probably 1875 Eusarcus Grote & Pitt, p. 1 [preoccupied by Eusarcus Perty, goes some way towards explaining this. In this context, 1833 (Opiliones)] Strand also gets a mention in the review by Evenhuis 1942 Eusarcana Strand, p. 387 [replacement name] (2008) of the so-called ‘Mihi itch’, or its German var- 1964 Paracarcinosoma Caster & Kjellesvig-Waering, p. 312. iant ‘Mihisucht’ – a term Strand apparently coined Type species. Eusarcus scorpionis Grote & Pitt, 1875. himself in response to Mortensen (1929)! This ‘itch’ is Included species. E. acrocephala (Semper, 1898), E. obesa (Wood- essentially an insatiable desire to name taxa. ward, 1868). Strand’s name was completely overlooked. Eusarcana Remarks. Eusarcus Grote & Pitt, 1875 was proposed has not been mentioned in any subsequent eurypterid for a eurypterid from the Buffalo Waterlime of New publications, including summary works such the Trea- York State, USA with Eusarcus scorpionis Grote & Pitt, tise (Størmer 1955), the systematic overview of Toller- 1875 as the type species by original designation. The ton (1989), or the online summary of nomenclature by genus name is preoccupied. Eusarcus Perty, 1833 was Dunlop et al. (2011). As long as only Carcinosoma re- already in use for (living) laniatorid harvestmen (Ara- mained in use this was not really an issue and Strand’s chnida: Opiliones: Gonyleptidae); a genus recently re- name could effectively be ignored. However, Caster & vised by Hara & Pinto da Rocha (2010). The homonym Kjellesvig-Waering (1964), in their major revision of was not initially recognised and Eusarcus continued to Mixopteroidea, created a new genus Paracarcinosoma be used for eurypterids throughout the late 19th and Caster & Kjellesvig-Waering, 1964 with Eusarcus scor- early 20th centuries (e.g. Clarke & Rudemann 1912; pionis as the type species. Eusarcus had effectively Kindle 1913; Woodward 1913; Williams 1915; O’Con- been revalidated, but Strand’s Eusarcana was not men- nell 1916; Ruedemann 1919; Diener 1924). tioned by Caster & Kjellesvig-Waering and they were Another scorpion-like eurypterid was described as presumably unaware of its existence. Indeed, Caster & Eurysoma newlini Claypole, 1890a from Kokomo in In- Kjellesvig-Waering (1964: 312–313) simply introduced diana, USA. Eurysoma Claypole, 1890a is also preoc- the name Paracarcinosoma as a new genus and made cupied and the name has been introduced independently no mention of any previous nomenclatural discussions. on at least six occasions; the oldest of which was for a Paracarcinosoma has been used by all subsequent beetle Eurysoma Dejean, 1831 (Insecta: Coleoptera). authors working on carcinosomatid eurypterids (Stør- Claypole quickly recognised the homonym (Fig. 2) and mer 1974; Copeland & Bolton 1985; Tollerton 1989; proposed Carcinosoma Claypole, 1890b as a replace- Ciurca 1990; Braddy & Dunlop 2000; Braddy et al. ment name for his genus – again with Eurysoma new- 2002; Tetlie 2007; Tetlie et al. 2008; Lamsdell & Braddy lini as its type species. Clarke and Ruedemann (1912) 2010; Dunlop et al. 2011) – with the exception of compared Carcinosoma with Eusarcus and concluded Ritchie (1968) who still considered the Paracarcinoso- in their monograph that the two genera were synonyms. ma species to belong to Carcinosoma. Priority went to Grote & Pitt’s older name, Eusarcus, We are thus faced with the following nomenclatural whereby the fact that it was also a homonym had still problem for Paracarcinosoma scorpionis. Does the not been recognised. Principle of Priority force us to revert to the next oldest In his discussion of his new family Carcinosomati- available name and treat Eusarcana scorpionis (Grote dae, Størmer (1934) now realised that Eusarcus was & Pitt, 1875) as the correct name? Could the Interna- preoccupied by a harvestman and (correctly)