Eutrachelophiini, Myers & McDowell, 2014

Myers, Charles W. & McDowell, Samuel B., 2014, New Taxa And Cryptic Species Of Neotropical Snakes (Xenodontinae), With Commentary On Hemipenes As Generic And Specific Characters, Bulletin of the American Museum of Natural History 2014 (385), pp. 1-112 : 6

Eutrachelophiini , new tribe

TYPE GENUS: Eutrachelophis , new genus.

CONTENT: One genus with three species from western and middle Amazonia (map 1).

DEFINITION AND DIAGNOSIS: Distinguished from all other snakes by the generic definition below. Tribal status is conferred primarily to express hypothesized relationship with the Xenodontini , which are defined mainly by the presence of hemipenial apical discs (lost in a few species as demonstrated herein). The Eutrachelophiini and Xenodontini have hemipenes (divided except in one species) with noncapitate capitula ornamented solely with spines and spinules and with the apices either nude or spiny; the sulcus spermaticus is divided proximally, with branches centrifugal or becoming so. Most ‘‘xenodontine’’ genera are characterized by hemipenes that are distally calyculate or flounced, frequently with some form of capitation. Few other genera of ‘‘xenodontines’’ are characterized by acalyculate spiny hemipenes.

REMARKS: The new tribe Eutrachelophiini is assigned to the Xenodontinae primarily on the basis of hemipenial comparisons with a cluster of genera (tribe Xenodontini ) that includes Liophis and the type genus Xenodon . Relationships among the various genera remain to be clarified.