Transactions and Proceedings of the Royal Society of New Zealand [electronic resource]

Volume 79, 1951

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^*1.	All vertebrae are amphicoelous.
*2.	Nine presacral vertebrae occur.
3.	The neural spines are not sharply defined.
^†*4.	The “atlas” vertebra lacks transverse processes.
*5.	Ribs are present in association with the third and fourth vertebrae and occasionally also with the fifth. Characteristic processes are developed on the ribs.
*6.	The sacral diapophyses are simple and relatively unexpanded.
7.	The sacral vertebra is typically narrower than the others and is formed of two separate bony halves joined dorsally and ventrally by cartilage.
8.	During development the urostyle is formed of a single hypochordal cartilage to which up to three postsacral vertebrae become fused.
9.	Fusions between successive vertebrae are not uncommon, especially between the first and second, and the fifth and sixth.
10.	The sacrum may occasionally be forwardly displaced to the ninth vertebra, thus producing a small postsacral vertebra, distinct from the urostyle.

[Footnote] * Characters in which Ascaphus is known to agree with Leiopelma.

[Footnote] † Characters in which Ascaphus may be considered to agree with Leiopelma, although the evidence is not conclusive.

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11.	Thirteen pairs of spinal nerves are usually present.
12.	The first spinal nerve is the N. suboccipitalis, which has a ventral root only. Some fibres from this nerve pass to the M. opercularis.
*13.	The pectoral girdle is arciferous, but the epicoracoids are united at their anterior tips.
14.	Overlapping of the epicoracoids may be left over right or vice versa.
*15.	The procoracoid may show partial ossification.
*16.	A cartilago paraglenoidalis separates the coracoid from the scapula.
*17.	A cleithrum is present.
18.	The sternum has two posterior styles.
19.	Abdominal ribs, which originate as cartilaginous strips, are present in the M. rectus abdominis and form a continuous series with the styles of the sternum.
*20.	A cartilaginous, shield-shaped epipubis is present. It may ossify in late maturity.
21.	Nobelian bones are absent.
22.	The pubis remains cartilaginous throughout life.
23.	A small phalangeal element lies distal to the metacarpal of the prepollex.
†*24.	The free adult carpal elements number eight.
25.	The prehallux is represented by a small metatarsal.
†*26.	Five free adult tarsal elements occur in addition to the tibiale and fibulare.