hyomandibular


Also found in: Dictionary, Wikipedia.

hyomandibular

[¦hī·ō‚man′dib·yə·lər]
(vertebrate zoology)
The upper portion of the hyoid arch in fishes.
References in periodicals archive ?
The second is the hyoid arch which, in these organisms, consists only of the hyomandibular cartilage, articulated to the neurocranium and the mandible.
Approximately 460 million years ago, the anterior gill arches of some aquatic vertebrates evolved into jaws and their supporting structures, including the hyomandibular bone.
A small sensory structure that develops in association with the hyomandibular cleft in vertebrate embryos (von Bartheld, 1990) is retained beyond early embryological development in only a few vertebrates (Simonetta, 1953).
Level two: Lateral view, right side of mandibular arch: 9, posterior limit of hyomandibular articular condyle; 10, dorsal tip of hyomandibular dorsal process; 11, anterior limit of hyomandibular opercular condyle; 12, anterodorsal limit of hyomandibular symplectic synchondrosis; 13, anterior limit of preopercular-quadrate suture; 14, posterodorsal limit of quadrate (in tricomycterids, this is represented by a slender dorsal process, while in other loricarioids, the process is absent and the landmark is identified as the posterodorsal extremal limit of the quadrate); 15, anterior tip of quadrate mandibular condyle.
Fourth, fifth and sixth infraorbitals short and wide, covering posterior margin of hyomandibular. Supraorbital absent.
There is a series of conspicuous pores (hyomandibular pores) located behind the eye.
Levator hyomandibularis (LH): originates on the lateral wall of the neurocranium in the otic region, and runs anterolaterally inserting in the caudal part of the hyomandibular cartilage.
The hyomandibulosymplectic cartilage, consisting of cartilaginous precursors to the hyomandibular and symplectic, is visible at 5 DPH.
These synapomorphies are: mesocoracoid arch absent (104: 0 [right arrow] 1, occurring in some groups outside of this clade C22 and reverted inside of it in Osmerus + Plecoglossus); presence of peculiar, prominent hyomandibular lateral spur at or below the level of the opercular process (196: 0 [right arrow] 1, within the fishes examined, occurring exclusively in the taxa of this clade C22 and only reverted in Stokellia + Retropinna).
Peculiar, prominent hyomandibular lateral spur at or below the level of the opercular process, projecting caudally to contact the preopercle.