bidichotomous

English

Adjective

bidichotomous

1. (especially in malacology) Dividing or branching first into two branches, and then (in at least one of those branches) into two more branches.
   • 1925, Ernest Neaverson, Ammonites from the Upper Kimmeridge Clay, page 25:

     [...] two primaries immediately preceding it unite on the umbilical shoulder forming a bidichotomous bundle. The periphery is gently rounded and the cast shows a slight ventral groove, comparatively broad and shallow, on the peripheral [...]

   • 1978, Bulletin, numbers 298-302, Geological Survey of Canada, page 44:

     [...] bidichotomous or polyptychitid rib bundles appears rather early in the ontogeny of T. elegans.

   • 1988, Jurjiz Alexander Jeletzky, Edwin Kemper, Comparative Paleontology and Stratigraphy of Valanginian ..., page 147:

     [...] bidichotomous type is subordinate [...]