"Huene (1923: p. 453) referred to Lydekker's work, stating that "the species
described as _M. dunkeri_ by Lydekker (Dames) [sic], from the English (and
German) Early Wealden, is distinguished from _Megalosaurus_ by its
enormously high neural spines in the dorsal region. I therefore propose to
establish a new genus, _Altispinax_, for it. [snip]
"However, Huene (1926a: pp. 482-483) stated: "There is another specimen from
the Wealden of Battle...consisting of three articulated middle dorsal
vertebrae, with extremely high neural spines. ...if it were certain that
such dorsal vertebrae belong to _Megalosaurus dunkeri_, it would be
necessary to put it into a distinct genus, for which the name _Altispinax_,
gen. nov., might be reserved.", and in 1932 (p. 235): "Three articulated
dorsal vertebrae with very elongated neural spines, figured by Owen (202,
Pl. 19), also seem to belong here; ...In 1926 ..., I based the genus
_Altispinax_ on these specimens." (my translation). From this it is clear
firstly that the generic name _Altispinax_ was proposed for the three
vertebrae, and secondly does not refer to the nomen dubium _Megalosaurus
dunkeri_. Since Huene (1926) did not propose a new specific name, the first
available species name given exclusively to the vertebrae is Paul's (1988a)
_Acrocanthosaurus altispinax_, the species thus becomes _Altispinax
altispinax_ (PAUL, 1988a). _Becklespinax Olshevsky, 1991, is thus an
objective junior synonym of _Altispinax_ Huene, 1923.
The gist of this nomenclatural saga would appear to be that when Huene first
coined the name "Altispinax_ in 1923 it may not have qualified as a valid
name under ICZN rules (this fits with what Mickey said about the
"conditional" nature of the name). However, Huene was more explicit in his
later publications, so by 1926 it is clear that he is basing _Altispinax_ on
the tall-spined vertebrae. So although Huene was wishy-washy in the
beginning about what he meant to attach the name "Altispinax" to, he later
cleared this up.