Tüm mevcut kafadan bacaklılar bukkal kitlede yer alan ve kaslı baş uzantıları ile çevrili iki kısımlı bir gaga

Tüm mevcut kafadan bacaklılar, bukkal kitlede yer alan ve kaslı baş uzantıları ile çevrili iki kısımlı bir gagaya veya (gaga şeklinde çıkıntı) sahiptir. Dorsal (üst) mandibula, ventral (alt) mandibulaya oturur ve birlikte makas benzeri bir şekilde çalışır. Gaga ayrıca mandibula veya ağız olarak da ifade edilebilir.

Bukkal kitle ve uzuvlarla çevrili dev kalamarın gagası

Fosilleşmiş gaga kalıntıları, kalamar, ahtapot, ve vampirromorf dahil olmak üzere hem mevcut hem de soyu tükenmiş bir dizi kafadan bacaklılar grubundan bilinmektedir. - bulunan eşleşmiş levha benzeri yapılar- aynı zamanda ağız/çene unsurları da olabilir.

Kaynakça

^ Young, R.E., M. Vecchione & K.M. Mangold (1999). Cephalopoda Glossary 6 Temmuz 2018 tarihinde Wayback Machine sitesinde .. .
^ Young, R.E., M. Vecchione & K.M. Mangold (2000). Cephalopod Beak Terminology 9 Aralık 2018 tarihinde Wayback Machine sitesinde .. .
^ ^a ^b Tanabe, K., Y. Hikida & Y. Iba (2006). Two coleoid jaws from the Upper Cretaceous of Hokkaido, Japan. Journal of Paleontology 80(1): 138–145. DOI:[0138:TCJFTU2.0.CO;2 10.1666/0022-3360(2006)080[0138:TCJFTU]2.0.CO;2]
^ Zakharov, Y.D. & T.A. Lominadze (1983). New data on the jaw apparatus of fossil cephalopods. Lethaia 16(1): 67–78. DOI:10.1111/j.1502-3931.1983.tb02000.x
^ Kanie, Y. (1998). New vampyromorph (Coleoidea: Cephalopoda) jaw apparatuses from the Late Cretaceous of Japan. Bulletin of Gumma Museum of Natural History 2: 23–34.
^ Tanabe, K. & N.H. Landman (2002). Morphological diversity of the jaws of Cretaceous Ammonoidea. Abhandlungen der Geologischen Bundesanstalt, Wien 57: 157–165.
^ Tanabe, K., P. Trask, R. Ross & Y. Hikida (2008). Late Cretaceous octobrachiate coleoid lower jaws from the north Pacific regions. Journal of Paleontology 82(2): 398–408. DOI:10.1666/07-029.1
^ Klug, C., G. Schweigert, D. Fuchs & G. Dietl (2010). First record of a belemnite preserved with beaks, arms and ink sac from the Nusplingen Lithographic Limestone (Kimmeridgian, SW Germany). Lethaia 43(4): 445–456. DOI:10.1111/j.1502-3931.2009.00203.x
^ Tanabe, K. (2012). Comparative morphology of modern and fossil coleoid jaw apparatuses. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 266(1): 9–18. DOI:10.1127/0077-7749/2012/0243
^ Morton, N. (1981). Aptychi: the myth of the ammonite operculum. Lethaia 14(1): 57–61. DOI:10.1111/j.1502-3931.1981.tb01074.x
^ Morton, N. & M. Nixon (1987). Size and function of ammonite aptychi in comparison with buccal masses of modem cephalopods. Lethaia 20(3): 231–238. DOI:10.1111/j.1502-3931.1987.tb02043.x
^ Lehmann, U. & C. Kulicki (1990). Double function of aptychi (Ammonoidea) as jaw elements and opercula. Lethaia 23: 325–331. DOI:10.1111/j.1502-3931.1990.tb01365.x
^ Seilacher, A. (1993). Ammonite aptychi; how to transform a jaw into an operculum? American Journal of Science 293: 20–32. DOI:10.2475/ajs.293.A.20

[ToL-1] Young, R.E., M. Vecchione & K.M. Mangold (1999). Cephalopoda Glossary 6 Temmuz 2018 tarihinde Wayback Machine sitesinde .. .

[2] Young, R.E., M. Vecchione & K.M. Mangold (2000). Cephalopod Beak Terminology 9 Aralık 2018 tarihinde Wayback Machine sitesinde .. .

[jaws-3] Tanabe, K., Y. Hikida & Y. Iba (2006). Two coleoid jaws from the Upper Cretaceous of Hokkaido, Japan. Journal of Paleontology 80(1): 138–145. DOI:[0138:TCJFTU2.0.CO;2 10.1666/0022-3360(2006)080[0138:TCJFTU]2.0.CO;2]

[4] Zakharov, Y.D. & T.A. Lominadze (1983). New data on the jaw apparatus of fossil cephalopods. Lethaia 16(1): 67–78. DOI:10.1111/j.1502-3931.1983.tb02000.x

[5] Kanie, Y. (1998). New vampyromorph (Coleoidea: Cephalopoda) jaw apparatuses from the Late Cretaceous of Japan. Bulletin of Gumma Museum of Natural History 2: 23–34.

[6] Tanabe, K. & N.H. Landman (2002). Morphological diversity of the jaws of Cretaceous Ammonoidea. Abhandlungen der Geologischen Bundesanstalt, Wien 57: 157–165.

[7] Tanabe, K., P. Trask, R. Ross & Y. Hikida (2008). Late Cretaceous octobrachiate coleoid lower jaws from the north Pacific regions. Journal of Paleontology 82(2): 398–408. DOI:10.1666/07-029.1

[8] Klug, C., G. Schweigert, D. Fuchs & G. Dietl (2010). First record of a belemnite preserved with beaks, arms and ink sac from the Nusplingen Lithographic Limestone (Kimmeridgian, SW Germany). Lethaia 43(4): 445–456. DOI:10.1111/j.1502-3931.2009.00203.x

[9] Tanabe, K. (2012). Comparative morphology of modern and fossil coleoid jaw apparatuses. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 266(1): 9–18. DOI:10.1127/0077-7749/2012/0243

[10] Morton, N. (1981). Aptychi: the myth of the ammonite operculum. Lethaia 14(1): 57–61. DOI:10.1111/j.1502-3931.1981.tb01074.x

[11] Morton, N. & M. Nixon (1987). Size and function of ammonite aptychi in comparison with buccal masses of modem cephalopods. Lethaia 20(3): 231–238. DOI:10.1111/j.1502-3931.1987.tb02043.x

[12] Lehmann, U. & C. Kulicki (1990). Double function of aptychi (Ammonoidea) as jaw elements and opercula. Lethaia 23: 325–331. DOI:10.1111/j.1502-3931.1990.tb01365.x

[13] Seilacher, A. (1993). Ammonite aptychi; how to transform a jaw into an operculum? American Journal of Science 293: 20–32. DOI:10.2475/ajs.293.A.20