AMERICAN MUSEUM NOVITATE Published by Number 1320 the AMERICAN MUSEUM of NATURAL HISTORY May 28, 1946 New York City

AMERICAN MUSEUM NOVITATE Published by Number 1320 THE AMERICAN MUSEUM OF NATURAL HISTORY May 28, 1946 New York City PALAEOGALE AND ALLIED EARLY MUSTELIDS BY GEORGE GAYLORD SIMPSON INTRODUCTION The European Oligocene and, to some with Matthew's statements (see below) extent, late Eocene and early Miocene are that Bunaelurus is distinguished from characterized by an abundance of small Palaeogale only by the presence of M2. I carnivores varied and often confusing in called the importance of this find to the structure and affinities. They seem to in- attention of the late Dr. Walter Granger, clude intermediate or transitional types who was particularly interested in this between canids, mustelids, viverrids, and subject because it also bears on some of his felids (groups that are sharply distinct in Mongolian discoveries and researches. the recent fauna), to such a degree that the He proposed that we should make the distribution of these genera among estab- necessary wider comparisons in connection lished families is not satisfactory at present with the Asiatic faunas, and the specimen and may in part be quite arbitrary. was put away for future study. His death Among these genera there are, neverthe- and my absence in military service caused less, some that can be placed without seri- the specimen to be temporarily forgotten, ous question, and this is particularly true but it came to light again after my return of a few in which the dentition, cranial as I checked several such projects left un- foramina, and other characters appear to finished by Dr. Granger. The present note be unmistakably mustelid. This is no- is an attempt to carry out the study tably true of the genera Palaeogale, Plesio- planned by him. gale (hitherto confused with Palaeogale), The results of this study, given in more and Plesictis. These genera are of peculiar detail and with the necessary evidence on interest not only because they include the later pages, were surprising. It was earliest definitely recognizable mustelids, found that the specimen in question belongs but also because at least two of them are both to Bunaelurus and to Palaeogale, in remarkably widespread and have an in- other words that these names are synony- teresting bearing on intercontinental migra- mous. Their previous separation has been tions and correlations. It will be shown in due in part to inadequate knowledge of the the present paper that Palaeogale, al- variation of the dental formula in these though hitherto reported as a European animals and in part to comparison not with genus, also occurs in Asia and in North Palaeogale, strictly speaking, but with a America and that a relatively primitive group of European species that now ap- form of Plesictis (possibly generically or pears to be generically separable. For subgenerically separable from the later and this group the name Plesiogale is available, more typical species) is common to Europe and the distinction of Plesiogale from Pa- and North America, at least. laeogale, with which it has long been con- This brief study had its origin in at- sidered synonymous, is a second un- tempts to identify a skull and jaws found expected result of this study. Mongolian by Albert Thomson in the Big Badlands specimens referred in publication to Bun- in 1937. In labeling that year's collection aelurus and later in manuscript to Palaeo- I noted that this specimen resembles gale are also briefly reviewed and are found Bunaelurus but lacks M2 and therefore to be true Palaeogale, completing the link labeled it as Palaeogale sp., in accordance between Europe and North America as 2 AMERICAN MUSEUM NOVITATES [No. 1320 regards these Oligocene mustelids. A accompany them on their travels, are not comment on Mustelavus is appended, sug- discussed in this short contribution. New gesting that this genus is perhaps a definitions of Palaeogale, Plesiogale, and synonym of Plesictis, or perhaps a sepa- Plesictis are given, but discussion of their rable genus but, if so, one that probably broader affinities is deferred for a more should include some European Plesictis. general study of the family. In either case, this genus also exemplifies Besides finding the specimen out of which the Oligocene faunal interchange between this study grew, Mr. Thomson prepared it. the Old World and the New. Wider Mr. John C. Germann prepared the ac- problems involved in this interchange, for companying illustrations. Dr. G. L. Jep- instance the apparent failure of the more sen kindly lent the fine Princeton specimen viverroid associates of these mustelids to of "Bunaelurus." EUROPEAN PALAEOGALE AND PLESIOGALE The nomenclatural and general taxo- is type of Palaeogale. It is true that nomic situation regarding the European Helbing (1917, p. 440) explicitly desig- mid-Tertiary mustelids is quite confused nated P. angustifrons as "Typusspecies" and will be discussed here only as far as of Palaeogale, but this is necessarily invalid necessary to clarify the status and relation- because that species was unknown to the ships of American and Asiatic forms. For author when he defined Palaeogale. comparison with Bunaelurus, only the In 1847 Pomel proposed the genus European forms now customarily referred Plesiogale with the sole species P. angusti- to Palaeogale are closely pertinent. The frons. Various other species, or supposed genus Palaeogale was established by H. species, have from time to time been von Meyer in 1846. His definition was placed in Plesiogale, but P. angustifrons is brief and vague, but it clearly suffices to the type of the genus. (And, as noted establish the name as of that date under above, it is not available as type of Palaeo- the International Rules. Two species were gale.) named, P. pulchella and P. fecunda, but Schlosser (1887) placed angustifrons these were not distinguished. Gervais doubtfully in Palaeogale. He considered (1848-1852) later described a related (if Palaeogale and Plesiogale as synonyms and not identical) species as Mustela minuta. selected the former name for use on the Schlosser (1887) considered M. minuta the grounds that Plesiogale had also been used same as P. pulchella and called the species for species of Stenogale. This argument P. minuta. He listed P. fecunda as a has no bearing under the International separate species. More recent European Rules, but Palaeogale is the prior name as students (e.g., Viret, 1929) consider that noted above. Recent students, especially all three of these species, and probably one Helbing (1917, 1930) and Viret (1929), or two others, are synonyms and continue have referred angustifrons to Palaeogale to prefer P. minuta as the valid name. without question and have thus treated Both P. pulchella and P. fecunda are prior Plesiogale as a synonym of Palaeogale. in publication date, but it is possible to It has, however, been noted, especially by argue that they were not really defined until Viret, that there are (at least) two groups after P. minuta. The name to be used is of of species in Palaeogale as thus defined, a secondary importance, and I shall tenta- group of small species including P. minuta, tively use P. minuta in conformity with the P. felina (a Phosphorites species, older European students. The essential point than others referred to the genus), and is that the type of Palaeogale must be P. various possible synonyms, varieties or pulchella or P. fecunda and that if both allies, and a second group of larger animals these names are synonyms of P. minuta, represented mainly by P. angustifrons, as agreed by the competent recent workers, with a considerable number of close allies then the species currently called P. minuta or synonyms. 1946] PALAEOGALE AND ALLIED EARLY MUSTELIDS 3 It may now be emphasized that these two de Palaeogale. ." Viret also described species groups represent the two proposed and figured, unfortunately not very clearly, genera Palaeogale, type minuta, and another upper jaw of P. minuta in which Plesiogale, type angustifrons. It will ap- Ml is shown for the first time. pear from the following discussion that The fallacy in Helbing's treatment of -these groups do almost certainly represent this problem is, again, that he considers distinct, valid genera. Unfortunately, an- differences from P. angustifrons as ipso gustifrons, the best-known species, has facto differences from Palaeogale and does been used almost exclusively in defining not consider the alternative, which turns Palaeogale and in comparing that genus out to be correct beyond much doubt, with others, especially by Helbing. Thus that angustifrons, itself, does not belong the characters usually ascribed to Palaeo- in Palaeogale. The characters taken as gale in the literature are really those of excluding the skull parts in question from Plesiogale and belong to Palaeogale only Palaeogale now seem, in fact, to be generic when they happen to be shared by the two characters of Palaeogale excluding angusti- genera. The clear contrast between frons from that genus. Thus Viret's "Bunaelurus" and "Palaeogale" drawn by "rameau bien particulier" -is simply true Helbing -(1917) is in reality a contrast be- Palaeogale, and the angustifrons branch is tween Palaeogale (with which Bunaelurus generically distinct as Plesiogale. is now found to be synonymous) and This important conclusion is strongly Plesiogale (to which Helbing's well-pre- suggested by the pul)lished data on the served "Palaeogale" specimen really be- European forms, summarized above. It longed)-a confusion engendered by Hel- receives its strongest support, however, bing's using angustifrons as if it were from American specimens hitherto placed typical of Palaeogale, instead of the less in Bunaelurus. As will be shown on the well-known minuta. following pages, these specimens demon- Palaeogale minuta (or the P. minuta strate the association in single individuals group) is represented chiefly by lower jaws, of lower jaws generically inseparable from in which the distinction between Palaeogale Palaeogale (and markedly distinct from and Plesiogale is very slight.

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