von Huene's Altispinax: a necessary clarification

[StephanPickering@cs.com]

       Altispinax von Huene 1923 was specifically predicated upon BMNH R1828, three articulated caudal dorsals + an undescribed associated dorsal. Richard Owen first described and illustrated them in 1855, assigning them rather erroneously to the Bathonian Megalosaurus. He mentioned other specimens, but these were never described or illustrated, now lost from the collections of BMNH. Koken in 1884 described a worn, indeterminate tooth as Megalosaurus dunkeri, illustrating the lost tooth in 1887. On the basis of plesiomorphic similarity to teeth from Cuckfield, Richard Lydekker in his 1888 catalogue assigned various specimens to M. dunkeri, a nomen vanum (= nomen dubium of current usage, but is a little more forceful). Among the Lydekker specimens were a set of articulated metatarsals, BMNH 2559,  Richard Owen ha!
d,!
!
 in 1858,  assigned to Hylaeosaurus, Lydekker subsequently making BMNH 2559 the type of his Megalosaurus oweni. von Huene's 1923 genus was a nomen nudum for Lydekker's hypodigm "distinguished from Megalosaurus by its enormously high neural spines in the dorsal region". However, von Huene did not designate a type specimen for Altispinax, nor is his description diagnostic.
       von Huene returned to Altispinax in  two 1926 papers, in the first, "The carnivorous Saurischia",  his hypodigm consisting of Dames's indeterminate tooth + BMNH R1828 + BMNH R1525 [right metatarsal IV], BMNH 2559 designated as ?Altispinax oweni, all considered similar to Megalosaurus parkeri. In his second 1926 paper, "On several known and unknown Saurischia", the indeterminate lost tooth is the "type specimen" and a partial skeleton (BMNH R604 + R1525) is the "type material" for Megalosaurus dunkeri, thinking that if the Sussex BMNH R1828 ("the species possesses enormously high neural spines in the dorsal region") were Megalosaurus dunkeri, then "the name Altispinax, gen. nov., might be reserved". Hence, BMNH R1828 was made the topotype of a taxon based upon an indeterminate, nondiagnostic, lost tooth. Megalosaurus dunkeri is not Megalosaurus Buckland 1824.
       In preparing my manuscript The Saurischian and Ornithischian dinosaurs: a bibliographical catalogue of suborders, families, subfamilies, genera, and species 1822-1984, I excerpted the 18 typewritten pages on von Huene's Altispinax as Altispinax Huene 1923 BMNH R1828 nomen conservandum. My manuscript received a copyright certificate dated 12 June 1984. In the course of further research (an ongoing process for all of us involved in dinosaur systematics), I returned to this taxon in 1990, and on 16 August 1990 published a further, 21 page typewritten excerpt.
       In this 1990 small publication, I reviewed the nomenclatural history (used in this communique), and designated BMNH R1828 as the lectotype of Altispinax lydekkerhueneorum, the paratype consisting of a partial skeleton (BMNH R604, R604a-b, R604d, 2 tooth crowns, a dorsal or pectoral, a partial right scapula, and a left metatarsal IV Lydekker briefly described in 1890). I also published a small note, in the paper, noting that with the paratype were various indeterminate iguanodont bones (which I listed). To my species I referred Lydekker's Megalosaurus oweni. My diagnosis reads:
       Tetanurae with dorsal spines up to five times the height of their respective centra; spines constricted just above the arch; pleurocoels shallow and short; centra with moderately flared ends; metatarsal IV with pro-
nounced distal divergence relative to II; relative to metatarsals II and IV, III is larger and stouter; metatarsals II-IV with distinct distolateral and dorsomedial shoulders.
       I reprinted this small paper, with minor revisions on 25 July 1994 (reprinted 10 February 1995), and a reprinting (slightly revised) on 16 August 1995.
       Thus: 
       Altispinax von Huene 1923 BMNH R1828 nomen conservandum
       = Becklespinax Olshevsky 1991 BMNH R1828 nomen rejectum
       = Valdoraptor Olshevsky 1991 BMNH 2559 nomen rejectum
       Altispinax lydekkerhueneorum Pickering 1990 BMNH R1828
       =   Megalosaurus oweni Lydekker 1889 BMNH 2559 nomen dubium
       = ?Acrocanthosaurus altispinax G.S. Paul 1988 nomen nudum
       = Becklespinax altispinax Olshevsky 1991 BMNH R1828 nomen rejectum et nudum
       = Valdoraptor oweni Olshevsky 1991 BMNH 2559 nomen rejectum et nudum