| REFERRED MATERIAL. 
_ & Taquet (1982), BMNH R167 an incomplete left femur (see below) 
HOLOTYPE. BMNH R184 and BMNH R185, associated left and 
right femora. 
FEMUR OF HYLAEOSAURUS ARMATUS 
HORIZON AND LOCALITY. Hastings Beds, Upper Valanginian, 
Lower Cretaceous (Rawson ef al. 1978). Tilgate Forest, Cuckfield, 
| West Sussex, England. Wealden Shales, Barremian, Lower Creta- 
| ceous (Rawson et al. 1978), Isle of Wight, England. 
Specimens listed by Galton (1975), Galton 
_ and BMNH R170 (now registered as BMNH R12440) the proximal 
| portion of a right femur (see below). 
DESCRIPTION AND COMPARISON 
Lydekker (1888) referred a number of unassociated limb bone 
fragments (BMNH R170) to Hypsilophodon foxii (Huxley). Galton 
(1975) noted that two of the femoral fragments within BMNH R170 
differed significantly from the majority of femora attributed to this 
_ genus. InH. foxiithe distal end of the femur has a moderate posterior 
intercondylar groove and lacks an appreciable anterior intercondylar 
groove. Proximally, the lesser trochanter is separated from the 
_ greater trochanter by a narrow cleft (Galton 1974). Galton (1975) 
showed that the two specimens in question possess a distinct anterior 
Jintercondylar groove and he referred these specimens (now regis- 
tered as BMNH R8420 and BMNH R8421) to Valdosaurus 
\(=Dryosaurus) canaliculatus, a dryosaur from the Wealden of the 
Isle of Wight (Galton 1977, Galton & Taquet 1982). Examination of 
the specimens remaining within BMNH R170 has yielded a proxi- 
mal femoral fragment (Fig. 2a) in which the lesser trochanter is 
separated from the greater trochanter by a deep cleft (Fig. 2b). This 
jfeature is characteristic of the Dryosauridae (sensu Sues & Norman 
1990) and the locality and horizon from which the specimen comes 
‘suggests that it is referable to Valdosaurus canaliculatus, BMNH 
R12440. Several limb bone fragments attributable to H. foxii remain 
as BMNH R170. 
Galton (1975) suggested that a small right tibia (BMNH R124), 
previously listed as [guanodon sp. (Lydekker 1888) was also refer- 
124 appears to be more similar to that of /guanodon than to that of 
H. foxii. In Iguanodon the cnemial crest is longer than in H. foxii. In 
ddition, the cnemial crest of /guanodon swings laterally near its 
anterior margin (see Fig. 3). On the basis of these characters BMNH 
R124 is referred to/. cf. atherfieldensis Hooley. The small size of the 
specimen suggests that it belonged to a juvenile. 
Rn to H. foxii. However, the form of the proximal end of BMNH 
cnemial crest 
a b Cc 
fig. 3 Proximal right tibiae; 3a, b, /guanodon atherfieldensis Hooley, 
1924: 3a, after Norman 1986, 3b, BMNH R124; 3e, Hypsilophodon 
foxii (Huxley), after Galton 1974; anterior is towards the top; drawings 
not to scale. 
117 
ON THE STATUS OF CAMPTOSAURUS 
VALDENSIS (Lydekker, 1889) 
The femur BMNH R167 (Fig. 4) has proved something of an 
enigma. Lydekker (1888) listed it as H. foxii, but suggested that it 
may represent a distinct species of Hypsilophodon due to its greater 
size. Later, Lydekker (1889) suggested that BMNH R167 shared a 
number of similarities with the femur of his new species 
Camptosaurus leedsi, and he designated BMNH R167 the holotype 
of another new species, Camptosaurus valdensis. However, Gilmore 
(1909) noted several differences between C. valdensis and the North 
American Camptosaurus dispar Marsh, 1879 (the type species of 
the genus). For example, the fourth trochanter of C. dispar is situated 
on the distal half of the femoral shaft, whilst in C. valdensis the 
fourth trochanter is more proximally placed. Galton (1974) sug- 
gested that this and several other features indicated that BMNH 
R167 was not referable to Camptosaurus, but was in fact a large 
specimen of H. foxii. The use of C. leedsi as a representative 
specimen for Camptosaurus was also in error. Galton (1980) showed 
that the holotype of C. /eedsi (a femur, BMNH R1993) differs from 
North American Camptosaurus in lacking a deep anterior inter- 
condylar groove and by having a proximally placed fourth trochanter. 
Due to these and other features, Galton (1980) made Camptosaurus 
leedsi the type species of a new genus Callovosaurus, which is now 
regarded as Camptosauridaenomen dubium (Norman & Weishampel 
1990). Placing Camptosaurus valdensis is difficult as the areas that 
provide most of the features used in distinguishing between 
ornithopod femora, the form of the distal end and the shape and 
position of the lesser trochanter, are either missing or badly dam- 
aged. Sues & Norman (1990), in their recent review of the 
Hypsilophodontidae, regard BMNH R167 as Hypsilophodontidae 
nomen dubium. It is suggested here that Camptosaurus valdensis 
Fig. 4 Camptosaurus valdensis (Lydekker, 1889). BMNH R167, anterior 
view, showing the anterior intercondylar groove; abbreviations: ant.gr. = 
anterior intercondylar groove, les.tr. = position of lesser trochanter, 4th 
tr. = fourth trochanter; scale bar = 20 mm. 
