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In 1917 Dr. G. M. Allen and Lieut. James Lee Peters visited Porto
Rico in the interest of the Museum of Comparative Zoölogy. They

explored with great success a large cave near Ciales and found in the
floor, under an opening in the high domed roof, a considerable num-
ber of both mammal and reptile bones.

The latter have recently been sorted out and substantiate the state-
ment which I made some time ago (Proc. Biol. Soc. Wash., 30, 1917,
p. 98) when I said that I believed Dr. Allen had found jaws of Cyclura.
In 1918 Miller (Proc. U.S. Nat. Mus., 54, 1918, p. 509, pl. 81) named
Cyclura mattea2 from shell heaps in St. Thomas, — a species which
proves to be very closely related indeed to the form which I am about
to name. It is perhaps not remarkable that the Rock Iguana evidently
became extinct in Porto Rico at an early time. It was probably exter-
minated by the considerable population of Porto Rican Indians before
the Conquest, because no tradition of its existence seems to remain
amongst either living inhabitants or in the literature. The description
of this species likewise fills the last considerable gap in the known dis-
tribution of the genus and confirms the surmise ventured by Mr. Noble
and myself that Rock Iguanas had formerly been much more widely
distributed than their present dispersal would indicate. The limits of
the range of the genus coincided exactly with those of the Greater
Antillean subregion, including the Bahaman province and thus the dis-
tribution of the genus becomes at once more suggestive as it becomes
more completely definable.

This form may be known as Cyclura portoricensis, sp. nov.
Type, M.C.Z. No. 12,460, from the floor of the cave near Ciales,

Porto Rico, collected by Allen and Peters in February, 1917; being the
extremities of a left humerus.

Paratypes: A femur; tibia; two ulnae; a sacral and several dorsal ver-
tebrae; several incomplete mandibles; as well as a number of other
bones less perfect.

The extremities of a fully adult humerus are chosen for the type
for comparison with the type of Miller’s C. mattea, also a left humerus.
The two species are evidently very closely related, more so with each
other than with other neighboring species of Cyclura, viz., pinguis of
Anegada or stejnegeri and cornuta. The species differs from mattea in
being even larger and more massive. (Cf. Miller, l. c., pl. 81, fig. 4 and
5.) The bones figured herewith are life size as are those figured by
Miller. The greatest diameter of the expanded proximal extremity of the
type humerus (fig. G) is 35 mm. In an adult Cuban Rock Iguana (C.
macleayi3) about three feet long (M.C.Z. 6915 Santiago de Cuba; Col.
Wirt Robinson, coll.) the same dimension is 19 mm.

U.S.N.M. 59,359, humerus, paratype of C. mattea, is before me
and in this example the distal expansion is 30 mm. and the proximal
extremity though broken appears to be correspondingly smaller and less
massive. The bicipital depression or radial fossa in mattea is very con-
spicuously deeper and more extensive than in portoricensis; in this
respect the latter is even more like stejnegeri or cornuta than is mattea.
This is what one would expect from its geographic station.

Portoricensis was so far as known the largest member of the entire
genus.

I wish to thank Dr. Stejneger and Mr. Miller for permission to
compare the paratype of mattea with the material in hand.

There is no reason to believe that man has played any part in the
dispersal of Cyclura, as has beyond doubt been the case with the spread-
ing of Iguana through the Antilles. The distribution of Iguana is
absolutely haphazard, while that of Cyclura, as now definable, is typical
of those forms which spread by non-fortuitous or natural means.
Cyclura undoubtedly occurred in comparatively recent times on every
suitable island which has remained of the once more extensive Greater

Antillean land. It is improbable that this list of species with their habi-
tats could be the result of chance dispersal when it is considered that
not one Cylura is found elsewhere

C. macleayi Gray, Cuba and surrounding Cayos.
C. caymanensis Barbour and Noble, Cayman Islands.
C. baeolopha Cope4, Andros Isl., Bahamas.
C. inornata Barbour and Noble5, Exuma Keys, Bahamas (extinct?).
C. rileyi Stejneger, Watlings Isl., Bahamas.
C. nuchalis Barbour & Noble6, Fortune Isl., Bahamas (extinct?).
C. carinata Harlan, Turks and Caicos Isls., Bahamas.
C. collei Gray, Jamaica and surrounding cays (extinct?).
C. cornuta (Bonnaterre), Haiti and neighboring islets.
C. nigerrima Cope7, Navassa Isl. (extinct?).
C. stejnegeri Barbour & Noble, Mona Isl.
C. portoricensis Barbour, Porto Rico (extinct).
C. mattea Miller, St. Thomas (extinct).
C. pinguis Barbour, Anegada (extinct?).

The existing place names and early literature and tradition prove
that Cyclura was previously found upon many other Bahaman Islands
where it has completely disappeared.

EXPLANATION OF THE PLATE.
A. Ventral view of left femur.
B. Ventral view of left tibia.
C. Dorsolateral view of left ulna.
D. Dorsolateral view of right ulna.
E. Posterior view of first sacral vertebra.
F. Dorsal view of distal extremity of left humerus.
G. Dorsal view of proximal extremity of left humerus.

44 IGUANA  •  VOLUME 12, NUMBER 1  •  MARCH 2005 HISTORICAL PERSPECTIVES

A New Rock Iguana from Porto Rico1

Thomas Barbour

1 From the Proceedings of the Biological Society of Washington
32:145–148 (1919).

2 Both Cyclura mattea and C. portoricensis are now considered syn-
onyms of C. pinguis.

3 Now considered a synonym of C. nubila.
4 Now considered a synonym of Cyclura cychlura cychlura.
5 Currently considered a subspecies of Cyclura cychlura.
6 Currently considered a subspecies of Cyclura rileyi.
7 Now considered a synonym of Cyclura onchiopsis.




