Rhinolophus lepidus, Blyth

Andersen, Knud, 1905, On some Bats of the Genus Rhinolophus, with Remarks on their Mutual Affinities, and Descriptions of Twenty-six new Forms., Proceedings of the Zoological Society of London 2, pp. 75-145 : 135-138

General Remarks on the Rhinolophus lepidus Group.

The ancestral species.— The ancestors of the simpleX and lepidus groups were very closely related. The latter had a projectingconnecting process, a slightly smaller skull and teeth. But the general shape of the skull, the dentition, the nose-leaves, apart from the process and a very slight difference in the shape of the sella, the ears, the wing-structure, the length of the tail, and, we might even say, probably the size, were either identical or extremely similar in both of these extinct Bats.

The place of origin. —There can scarcely be any doubt that the lepidus group originated much farther westwards than the simpleX group. If we regard Japan as a continental group of islands, and put aside Java, on account of its peculiar geological history, we still find, not only the most primitive, but in fact all the species of the lepidus section on the Continent. It is only the section which has spread over the adjacent larger islands, one of which (Sumatra) has comparatively recently been continental, while another (Java), probably in a more remote period, seems to have been connected with some part or other of Indo­ China; and only one form, still so closely related to the Java species as hardly to be specifically different, has found its way so far eastwards as Lombok. The hypothesis, therefore, cannot be called unfounded, that of the two ancestral species, the ancient 1 simplex ” and the ancient 11 lepidus , ” the former was Eastern in range (Austro-Indo-Malayan), the latter Western (Oriental).

Differentiation*.— From a systematic point of view I found it convenient to divide the lepidus section into three “types ”; I think that, phylogenetically speaking, there are two only: the lepidus and the minor type. The former, as coming nearest to simpleX in the proportionate size of the skull and teeth, is, probably, the more primitive; it is now distributed over the Indian Peninsula ( lepidus ), the Himalayas ( monticola ), and Malacca ( refulgens ). The latter, the minor -type, has spread from the Himalayas (minor) eastwards through S. China to Japan ( cornutus ); it is represented on the now quite isolated Anambas Islands (“ minutus ”); its occurrence in Java is not surprising, considering

the faunistic affinities of that island; and it has established itself on the western coast of the Indian Peninsula ( gracilis ). I have but very little doubt that now, when attention has been called to the differences of all these forms of the minor-type, it will be found also in other parts of the Indian Peninsula.

If any inference can be drawn from fragments of a skull and the external characters, the subbadius-type would appear to be an offshoot of the minor-type: already in minor and cornutus the process is a little sharper-pointed than in lepidus ; in subbadius and monoceros this tendency is carried much further.

The skull of the species of the acuminatus section (Java- Lombok, Sumatra-Engano) is of the lepidus-ty pe; the process too; the colour remarkably like that of refulgens . This leads me to suppose that acuminalus and its allies ( sumatranus , calypso ) are scarcely more than giant representatives of the lepidus-type.

It is the subbadius- type which, from a zoogeographical point of view, is by far the most interesting: it has spread southwestwards over a vast part of the Ethiopian Region, and westwards over the Mediterranean countries:—

(1) The empusa-type.— Rh. empusa * and blasii have progressed further on the way already indicated by Rh. subbadius . They have the small skull and the small teeth characteristic of minor- subbadius ; in the shape of the skull there is no essential difference; the dentition is identically the same; the process is that of a sub­ badius; the sella is deltoid, that is: the tendency, in the subbadius- sella (as emphasised above), towards assuming a subacute summit has been further developed; and we still see the constriction at the middle of the sella. But empusa and blasii are (as always the Ethiopian and W. Palaearctic species) in several points more highly developed: III.2 is lengthened (about, or more than, 1 the length of III1.); also IV.2 is very much longer (not far from twice the length of IV 1.). Rh. empusa is, however, an inhabitant of Nyasa- land, far S. of the Equator, Rh. blasii of the Mediterranean Subregion; thus, the two extremely closely allied species are now separated by an enormous tract, where no relative appears to occur. As we now know that they are descendants of the Oriental subbadius-type, the explanation seems to be quite clear: one branch spread south west wards, into the Ethiopian Region, and developed into Rh. empusa (slightly more primitive dentition; shorter ears, broader horse-shoe); another westwards into the Mediterranean countries, Rh. blasii . There is an instructive fact connected with these two Bats: I believe them to be comparatively recent intruders into their areas; Rh. empusa is known from one specimen only, from the very East of Tropical Africa; Rh. blasii is much more common in the Eastern Mediterranean tract, and still it does not seem to have reached Spain t.

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(2) The landeri-euryale type. — The Ethiopian Rh. landeri (Fernando Po, Gaboon), h. lobatus (Lower Zambesi to Mombasa), and Rh. dobsoni * (Kordofan) have the small skull and the small teeth characteristic of minor-subbadius; the same shape of the skull; the same dentition (no vacillation in the position of p); the process is that of a subbadius . In so far there is no difference at all between this section and the former (empusa-blasii). But in the shape of the sella and in a certain peculiarity in the wingstructure they have taken a course of their own:—We have seen, in the simpleX group, a progressive development from a sella constricted at the middle, through a parallel-margined stage, to a pandurate sella; we have seen in the lepidus group, too, the constricted sella {minor) modified into the parallel-margined ( gracilis ); the Ethiopian species here under consideration represent the third and final stage, the pandtvrate sella. In addition to this: in all of them IV.1 is peculiarly shortened’, less than (extremely rarely, as a slight individual atavism, equal to) half the length of IV2. As in Rh. empusa and blasii , III.2 is lengthened.

Rh. euryale , from the Mediterranean Subregion, is so extremely closely allied to the above-named Ethiopian species that it shares with them all essential characters (even the highly peculiar shortening of TV. 1), with one exception: it has retained the parallelmargined sella.

Summary.— When discussing the affinities of the Ethiopian species of the Rh. simpleX group (above, pp. 117-20), I arrived at the conclusion that they are undoubtedly derived from Oriental types, and that, most probably, the ancestral species have spread directly from South Asia into the Ethiopian Region.

As will be observed from this, a study of the Ethiopian representatives of the Rh. lepidus group leads to quite the same result: they have their closest known allies in the Oriental Region, but they are, without exception, considerably more highly developed than any of their Oriental relatives. Bats of the subbadius- type have evidently spread from some part of South Asia south westwards into the Ethiopian Region { empusa ; landeri , lobatus , dobsoni), and westwards over the Mediterranean countries ( blasii ; euryale ). Of all the species of the Rh. lepidus group only one has found its way to Lower Egypt, Rh. euryale .

It is a species exclusively Mediterranean in range, and unusually liable to differentiation into slightly differing local forms I.

Its presence in Lower Egypt is easily explained by invasion from the adjacent Asiatic coast of the Mediterranean, where it is very common (specimens from Lower Egypt are indistinguishable from the Palestine form, Rh. e. judaicus) J.

The probable affinities and phylogeny of the principal forms of the Rh. lepidus group are expressed in the subjoined diagram (Ethiopian types marked with an asterisk)