The Ants of Africa
Genus Tetramorium
Tetramorium angulinode Santschi

Tetramorium angulinode Santschi

return to group key Type location Congo (Tetramorium (Xyphomyrmex) angulinode, Santschi, 1910c: 385, illustrated, all forms) collected at Brazzaville, by A. Weiss; junior synonyms daphnis (Xiphomyrmex angulinode Sants v Daphnis n. var, Santschi, 1920b: 16, illustrated, worker & queen) from Zimbabwe, humerosum (Tetramorium humerosum, Emery, in litteris, Bernard, 1952: 13, illustrated, worker & queen) from Cameroun, collector L. Conradt, 1895, and papyri (Xiphomyrmex papyri, Weber, 1943c: 374, illustrated, queen) from Sudan (see Bolton, 1995) .

Santschi's (1910c) description is at {original description} and {original description} . Santschi's (1920d) description of daphnis is at {original description}. Arnold (1926: 279) gave a translation of daphnis, this is at {original description}. Weber's (1943c) description of papyri is at {original description}. Bernard's (1952) description of humerosum is at {original description} - this Bolton pointed out largely describes a specimen of ataxium, whereas the type specimens were what Bolton decided was angulinode. Bolton's modern description (1980) is at {original description}.

Fresh specimens, as shown below and on the linked pages, indicate that Bolton's blanket treatment, characteristic of his approach to the descriptions of the pioneer taxonomists, was erroneous.

The answer may lie in Santschi's style of designating varieties and "stirps" rather than new species for forms with somewhat similar overall morphology. The illustrations from Santschi (1920b) are good examples. Quite clearly the type form, as described and illustrated by Santschi, is not the form Bolton decided to re-define as angulinode. Re-examination of the specimen Bolton chose for his description and illustration (as is typical of his work, the drawn specimen is not labelled as to source), presumably could help resolve the conundrum. For now, however, I present what is available to me.

{Bolton Key}
{short description of image}

{Tetramorium angulinode}
This CAR specimen clearly closely matches all the details of the Santschi type form, with abundant, short, fine erect pilosity; also the pedicel nodes have the block-like profiles; contrary to Bolton's assertion, the petiole does not have any lateral carina
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{short description of image}
This Ghana specimen has mandibles that possibly are faintly rugose/striate but then the Bolton key would lead to Tetramorium edouardi, which this clearly is not
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{short description of image}
Santschi noted this as black with reddish appendages; the striations on the head clearer and less anastomosed on the occiput; petiole shorter, higher than long; postpetiole also shorter than the type and as long as the petiole; both nodes almost as strongly sculptured as the type; type location Zimbabwe.
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{short description of image}

{short description of image}
This Gabon specimen has smooth pedicel nodes which Bolton's key would lead to Tetramorium minisculum but the pilosity is quite unlike that species, see below. What it does have is the petiole profile and carina of the Bolton illustration, and, the relatively small narrow propodeal spines.
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{short description of image}

{short description of image}Tetramorium zapyrum; this specimen was identified by Bolton (who also had collected it in Nigeria); with distinct thick propodeal spines with a slight downcurve
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{Tetramorium minisculum} {Tetramorium minisculum}
Tetramorium minisculum - note the short propodeal spines, rather teeth; the Gabon specimens, which I have sighted from four collections, all have the dorsum of the petiole and postpetiole very finely puncturate, contrary to Bolton's separation as these being smooth, although he does note the sides of the segments as having "faint traces of sculpture".
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© 2007 - Brian Taylor CBiol FIBiol FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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