12 UPPER CRETACEOUS TELEOSTS 
Vertebral column. The entire vertebral column is shown in the restoration of the 
skeleton (Text-fig. 3). It consists of 40 vertebrae of which approximately 23 are 
precaudal and 17 caudal. The centra are slightly longer than they are deep and 
are considerably mesially constricted. Laterally the centra bear about three 
longitudinal raised ridges, but more posteriorly in the caudal region the lateral 
ridges are reduced to two. In the precaudal region neural spines are very fine and 
long with a prominent backward curvature, but in the caudal region the spines 
become shorter, stouter and straighter. All of the neural arches are intimately 
connected to the corresponding centra. The precaudal vertebrae bear small antero- 
ventral transverse processes with which pleural ribs articulate. The ribs are long, 
thin and strongly curved both posteriorly and ventrally around the body cavity. 
The enlargement and ventral prolongation of the transverse processes begins at 
about the z2oth precaudal vertebra and fusion occurs by the 24th vertebra. The 
haemal arches thus produced gradually become drawn out into backwardly project- 
ing haemal spines. Prezygapophyses and postzygapophyses are not prominent on 
the precaudal vertebrae but are more apparent caudally. 
Intermuscular bones, both epineurals and epipleurals, occur on the first 33 verte- 
brae. Anteriorly the epineurals articulate with the neural arches, but more post- 
eriorly the region of attachment rises on to the neural spines. Epipleurals anteriorly 
are associated with the centra, but in the caudal region associate with the haemal 
arches and spines. 
Median fins and tail. The fins are shown in the restoration of the whole skeleton 
(Text-fig. 3). The dorsal fin is made up of approximately 13 rays and is situated 
about mid-way between the occiput and the base of the caudal fin. The first ray is 
short and unbranched unlike the remainder which are longer and branched. All of 
the fin-rays are segmented. The proximal radials are long and thin with expanded 
head regions. The anteriormost radial has an expanded shaft region which bears a 
median anterior keel-like expansion. The distal ends of the proximal radials are 
expanded antero-posteriorly and inclined at a slight angle to the long axis of the fin; 
this is probably due to the fusion of the medial radials to the proximal radials. 
The anal fin is composed of 15 rays, situated behind the level of the posterior end of 
the dorsal fin. None of the proximal radials are expanded, all are thin and rod-like 
with only slightly expanded heads. The first ray is short and unbranched, the re- 
mainder are longer and branched. 
The caudal skeleton (Text-fig. 4) consists of six vertebrae, four preural vertebrae 
and two ural vertebrae, the second ural merely being a terminal half-centrum. 
Preural vertebrae 2, 3 and 4 all bear prominent neural and haemal spines which 
project more noticeably backwards than the spines of the vertebrae preceding them. 
The spines of these three preural vertebrae support the small accessory rays of the 
caudal fin. The first preural centrum is reduced in length and inclined slightly 
postero-dorsally. The haemal spine of preural 1 (the parhypural) is prominent and 
expanded. Dorsally the first preural vertebra does not bear a neural spine, simply an 
enlarged neuralarch. The first ural vertebra is even more reduced in extent than the 
first preural vertebra and is upturned. On its ventral edge the first ural vertebra 
bears two expanded hypurals which extend to the mid-line of the caudal fin. Ural 
