Broomulus dutoiti (Broom) Romer, 1947
Taxonomic History—Broom (1930) briefly described and
named ‘Lydekkerina’ dutoiti based on a specimen (MGM 4285;
Fig. 6) from the LAZ at Harrismith (Free State Province, South
Africa). Broom cited the presence of short, broad parietals,
coarse dermal sculpturing, and the exclusion of the supratemporal
from the otic notch margin as diagnostic of the species, based
largely on comparison with ‘Lydekkerina’ putterilli (Broom,
1930). Romer (1947) transferred ‘L.’ dutoiti to a new genus,
Broomulus, and listed as diagnostic several characters (our numbering):
(1) marked shortening of the face; (2) skull unusually
broad; (3) relatively closely spaced orbits; (4) contribution of the
lacrimal to the narial border; (5) (possible) minor contribution of
frontal to medial margin of orbit; (6) jugal broadly expanded
below orbits; and (7) sutural contact between postorbital and
parietal. Parrington (1948), Swinton (1956), and Kitching (1978)
regarded Broomulus dutoiti as a valid taxon, while Cosgriff
(1974) initially considered it incertae sedis within the Lydekkerinidae,
but later (Cosgriff, 1984) referred it to Lydekkerina
huxleyi. Hewison (1996) regarded the species as taxonomically
indeterminate within the Lydekkerinidae.
Shishkin and colleagues (1996) reexamined Broomulus dutoiti
and showed that, of the characters cited by Romer (1947), characters
1 and 6 were diagnostic of all lydekkerinids, the lacrimal
was regarded as being excluded from the narial margin (character
4), the frontal did not contribute to the orbital margin (character
5), and there was no sutural contact between the postorbital
and parietal (character 7). Romer’s character 3 was not
mentioned by Shishkin and colleagues (1996) but was presumably
regarded by the authors as tenuous. Hence, of Romer’s
characters, Shishkin and colleagues (1996) retained as valid only
the unusually broad skull (character 2). However, Shishkin and
colleagues (1996) listed an additional suite of characters of B.
dutoiti in support of the validity of that taxon. These included:
(1) more finely pitted dermal ornamentation; (2) small and
round orbits; (3) postorbital with a distinct anterolateral projection;
(4) broad lacrimal located well forward of the orbit; (5)
longer retroarticular process (
PGA) of the mandible that lacks
a distinct surangular eminence; and (6) tabular horns lack an
unsupported posterior projection. Schoch and Milner (2000), following
Shishkin and colleagues (1996), also regarded B. dutoiti as
valid and diagnosed it on the presence of a broad skull with
convex margins, short circumorbital (and adjoining) bones, wide
jugals, anterolaterally expanded (i.e., ‘hooked’) postorbitals, and
round orbits.