agnathous

English

Etymology

Ancient Greek ἀ- (a-, “without”) + γνάθος (gnáthos, “jaw”) +‎ -ous. From a- +‎ -gnathous.

Pronunciation

• enPR: ăgʹnə.thəs, IPA^(key): /ˈæɡ.nə.θəs/

Adjective

agnathous (not comparable)

1. Jawless.
   • 1876, William G. Binney, “On the Lingual Dentition, Jaw, and Genitalia of Carelia, Onchidella, and Other Pulmonata”, in Proceedings of the Academy of Natural Sciences of Philadelphia, page 185:

     The Onchidiidæ are described as agnathous, but I am confident of having observed the jaw figured.

   • 1900, Ramsay Heatley Traquair, “Notes on Drepanaspis Gmündenensis, Schlüter”, in Geological Magazine, page 158:

     The mouth is a transverse slit, which shows no teeth, nor any jaws properly so called, and therefore affords an apparent support to the agnathous theory of the Ostracodermi.

   • 1997, Gene S. Helfman, The Diversity of Fishes, Blackwell Science,, →ISBN, page 152:

     This and related agnathous (jawless), finless forms inhabited shallow seas or estuarine habitats[…].

   • 2007, James Brown, “Sequencing the Braden Style within Mississippian Period Art and Iconography”, in Ancient Objects and Sacred Realms, University of Texas Press, →ISBN, page 235:

     Parenthetically, this line treatment suggests an attempt to mimic the agnathous (jawless) head, if we suppose that the jaw area was colored suitably dark in contrast to the face proper.

2. (pathology) Afflicted by or characteristic of agnathia.
   • 1886, “Exhibition of Specimens: Meeting V”, Transactions of the Edinburgh Obstetrical Society‎^[1], volume 11, page 79:

     Dr Underhill exhibited an agnathous and hydrocephalic fœtus. This was an instance of the rare abnormality due to defect of the lower jaw.

   • 1893, “Proceedings of the Anatomical Society of Great Britain and Ireland: November 1892”, Journal of Anatomy and Physiology‎^[2], volume 27, page xvii:

     Upon this view an agnathous fœtus may be regarded as sometimes due to a posterior dichotomy, which has ultimately become a complete separation, and in which the two fœtuses have developed equally during a considerable part of intra-uterine life.

   • 1964, M. W. Fox, “Anatomy of the Canine Skull in Low-grade Otocephaly”, Canadian Journal of Comparative Medicine and Veterinary Science, volume 28, pages 105–106:

     In all the neonates examined from the partially agnathous strain, there was no obvious agenesia of the lower mandible.

Synonyms

• (jawless): agnathic, jawless
• (afflicted by agnathia): agnathic

Related terms

• agnath
• agnatha
• agnathan

Translations

jawless — see jawless

characteristic of agnathia

• German: agnath

References

• agnathous in Oxford English Dictionary, volume I, 1888