
• (a.) Having the mandible suspended by the hyomandibular, or upper part of the hyoid arch, as in fishes, instead of directly articulated with the skull as in mammals; -- said of the skull.
Found on 
http://thinkexist.com/dictionary/meaning/hyostylic/

<anatomy, marine biology> Having the mandible suspended by the hyomandibular, or upper part of the hyoid arch, as in fishes, instead of directly articulated with the skull as in mammals; said of the skull. ... Origin: Gr. A pillar. ... (06 Mar 1998) ... 
Found on 
http://www.encyclo.co.uk/local/20973
 Hy`o·styl'ic  adjective
Hy`o·styl'ic  adjective [ 
 Hyo- + Greek ... a pillar.] 
 (Anat.) Having the mandible suspended by the hyomandibular, or upper part of the hyoid arch, as in fishes, instead of directly articulated with the skull as in mammals; -- said of the skull. 
Found on 
http://www.encyclo.co.uk/webster/H/80

hyostylic Having the mandible suspended by the hyomandibular, or upper part of the hyoid arch, as in fish, instead of directly articulated with the skull as in mammals; a reference to the skull.
Found on 
http://www.wordinfo.info/words/index/info/view_unit/2056/
  No exact match found.