Coba jelasin Lihat juga dari Pachyrhachis dalam bahasa melayu dong

Ular-ular fosil yang berkaki belakang:

Caldwell, M. W. & Lee, M. S. Y.  (1997).  A snake with legs from the marine Cretaceous of the Middle East.  Nature 386: 705-709.

Haas, G. 1979  On a new snakelike reptile from the Lower Cenomanian of Ein Jabrud, near Jerusalem. Bull. Mus. Nat. Hist. Nat., Paris, Ser. 4, 1, 51-64.

Haas, G. 1980   Pachyrhachis problematicus Haas, snakelike reptile from the Lower Cenomanian: ventral view of the skull. Bull. Mus. Nat. Hist. Nat., Paris, Ser. 4, 2:87-104.

Haas, G. 1980  Remarks on a new ophiomorph reptile from the Lower Cenomanian of Ein Jabrud, Israel.  In Aspects of Vertebrate History, in Honor of E.H. Colbert (ed. L.L. Jacobs), pp. 177-102.  Flagstaff AZ: Museum of Northern Arizona Press.

Lee, M.S.Y. and Caldwell, M.W. 1998.  Anatomy and relationships of Pachyrhachis, a primitive snake with hindlimbs.  Philosophical Transactions of the Royal Society of London: Biological Sciences 353: 1521-1552.

Lee, M.S.Y., Scanlon, J.D.  2002.  Snake phylogeny based on osteology, soft anatomy and behaviour.  Biological Reviews 77: 333-401.

et al. 2003 "The Anatomy and Relationships of Haasiophis terrasanctus, a Fossil Snake with Well-Developed Hind Limbs from the Mid-Cretaceous of the Middle East" Journal of Paleontology 77(3):536-558

Scanlon, J.D., Lee, M.S.Y., Caldwell, M.W. and Shine, R.  1999.  Paleoecology of the primitive snake Pachyrhachis.  Historical Biology 13: 127-152.