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In this section we provide a chronology
of taxonomic changes and phylogenetic arrangements concerning snakes of the
Lampropeltis mexicana complex: alterna, greeri, leonis, mexicana,
ruthveni, and webbi. The fact that such a summary is necessary is
testament to the historical difficulty in arriving at a satisfactory, robust
taxonomy for this group. This is, in part, a combination of the challenges
in acquiring needed specimens (hard-to-find snakes in hard-to-get-to places
in a country that has not always welcomed non-Mexican scientists), and a
group of snakes that apparently has experienced a rapid, recent radiation.
There is a murkiness concerning species boundaries (how many species are
represented?) and inter-species relationships. Indeed, it remains to be seen
just which forms belong in a “mexicana complex” or even if such a grouping
reflects evolutionary history.
What follows is a chronological list,
with annotations, of relevant published works. As new material comes to
light, this section will be updated. For additional references, or for links
to downloadable files, please check the
Bibliography page.
1884 — Garman, S.
The
reptiles and batrachians of North America, Part I, Ophidia. Memoirs of the
Museum of Comparative Zoology, Harvard 8(3):xxxi–185. Original description
of L. mexicana, based on two females collected near Cd. San Luis
Potosí (SLP).
1893 — Günther, A.
C.
Biologia Centrali-Americana: Reptilia and
Batrachia. 1885–1902: xx + 326 pp. Original description of Lampropeltis
leonis, based on a specimen from Nuevo Leon. The presumed type specimen
is illustrated by a line drawing, and clearly represents the leonis-phase
morph of “thayeri.” If one is to recognize the snake occurring in
Nuevo Leon-Tamaulipas-Coahuila as distinct from L. m. mexicana, the
correct name is L. m. leonis (or L. leonis).
1897 — Dugès, A.
Description
d'un Ophidien nouveau du Mexique (Oreophis boulengeri, g. et. sp. nn.).
Proceedings of the Zoological Society of London 1897:284–285. Dugès erected
a new genus and species for a specimen collected from the Sierra de Santa
Rosa, Guanajuato. This was later placed in the synonymy of L. mexicana
by Dunn (1922).
1902 — Brown, A. E.
A
new species of Ophibolus from western Texas. Proceedings of the
Academy of Natural Sciences of Philadelphia 53:612–613, pl. 34. Original
description of Lampropeltis alterna (as Ophibolus alternus)
from the Davis Mountains of west Texas.
1920 —
Blanchard, F. N.
Three new snakes of the genus Lampropeltis. Occasional Papers of the
Museum of Zoology, University of Michigan (81):1–10, 1 plate. Original
description of Lampropetis ruthveni, based on a specimen from
Patzcuaro, Michoacan.
1922 — Dunn, E.
R.
Note on Lampropeltis mexicana (Garman). Proceedings of the Biological
Society of Washington 35:226. Dunn places Oreophis boulengeri Duges
(1897), based on a specimen from Guanajuato, in the synonymy of L.
mexicana.
1924 — Loveridge,
A.
A new snake of the genus Lampropeltis. Occasional Papers of the
Boston Society of Natural History 5:137–139. Original description of L.
thayeri, based on a specimen collected at Miquihuana, Tamaulipas.
Loveridge clearly distinguishes this taxon from L. mexicana. He also
reports on four recently-collected specimens of L. mexicana from near
Alvarez, San Luis Potosí, which he erroneously (and inexplicably) refers to
L. leonis.
1942 — Smith, H.
M.
Remarks on the Mexican kingsnakes of the triangulum group.
Proceedings of the Rochester Academy of Sciences 8:197–207. Smith includes
two figures—dorsal and ventral views—of the type specimen of Oreophis
boulengeri Dugès (= L. mexicana); these are the same figures as
printed in Smith and Necker 1943. Smith examined the series of 12 known
specimens of L. mexicana from San Luis Potosí, comparing these to the
single Dugès specimen from Guanajuato, finding general pattern similarities.
He suggests that hemipenial characters place L. mexicana within the
triangulum group. Smith elaborates on the specimen of L. alterna
he obtained from just west of Saltillo, Coahuila (see Smith 1941 for
details), and on the basis of hemipenial morphology and color pattern,
acknowledges the relationship with L. mexicana, and further suggests
that L. leonis (at this time known from but a single specimen)
belongs with these two in a “mexicana subgroup.” Meanwhile, L.
ruthveni and thayeri are placed in a “pyromelana subgroup”
with knoblochi (then considered a full species), pyromelana,
and zonata.
1944 — Smith, H. M.
Snakes of the Hoogstraal Expeditions to northern Mexico. Zool. Ser. Field
Mus. Nat. Hist. 29(8):135–152. An early attempt to make sense of the
phylogeny of the mexicana group of snakes. Reports the collection of
3 specimens of L. leonis (leonis morphs), under the name L.
thayeri, from near Galeana, which until this time was represented only
by the type specimen. Examination of this new material caused Smith to
modify composition of his “mexicana subgroup” to include thayeri,
leonis, alterna, and mexicana.
1950 — Flury, A.
A new king snake from Trans-Pecos Texas. Copeia 1950(3):215–217. Original
description of Lampropeltis blairi, based on a single specimen from
Terrell County, Texas. Later, Tanzer (1970) would demonstrate that blairi
and alterna patterns could emerge from a single clutch, and blairi
was reduced to a junior synonym of alterna (the older of the two
names).
1961 — Webb, R. G.
A
new kingsnake from Mexico, with remarks on the Mexicana Group of the genus
Lampropeltis. Copeia 1961(3):326–333. Original description of L.
greeri from the Sierra Madre Occidental southwest of Ciudad Durango.
Webb placed greeri with other species of the mexicana group
based on color pattern elements. He also provides a B/W figure of the
holotype of thayeri.
1962 — Gehlbach, F.
R., and J. K. Baker.
Kingsnakes allied
with Lampropeltis mexicana: taxonomy and natural history. Copeia
1962(2):291–300. An early attempt to make sense of the phylogeny of this
complex. L. alterna, L. blairi, L. greeri, L. mexicana, and
L. thayeri are regarded as conspecific (under the oldest available name,
L. mexicana, with five subspecies). They propose that this “mexicana
complex” is distinct relative to L. doliata (= triangulum),
L. pyromelana, and L. zonata. The type (and only known) specimen
of L. leonis is briefly discussed, and this is regarded as a species
distinct from L. mexicana. List of museum material available at the
time.
1965 — Gehlbach, F.
R., and C. J. McCoy, Jr.
Additional
observations on variation and distribution of the gray-banded kingsnake,
Lampropeltis mexicana (Garman). Herpetologica 21(1):35–38. Report on
L. alterna from Coahuila. Refer a specimen from 42 mi S Cd Durango (UCM
21061) to mexicana x alterna, and regard the type specimen of
L. greeri as a mexicana x alterna intergrade. They thus
place greeri in the synonomy of L. m. mexicana.
1967 — Gehlbach, F.
R.
Lampropeltis mexicana.
Catalogue of American Amphibians and Reptiles 55:1–2. Review of the
taxonomy, distribution, and relevant literature of L. mexicana. At
this time, L. mexicana included the subspecies alterna, blairi,
mexicana, and thayeri. This was published just prior to Tanzer's
discovery that alterna and blairi phenotypes could be produced
in a single clutch.
1970 — Tanzer,
E. C.
Polymorphism in the mexicana
complex of kingsnakes, with notes on their natural history. Herpetologica
26(4):419–428. [Tanzer followed Gehlbach’s construction of L. mexicana
as a broadly defined taxon, inclusive of alterna, mexicana (+greeri),
and thayeri. Importantly, Tanzer demonstrated that L. mexicana
alterna and L. mexicana blairi were pattern morphs of the same
species, and that the name alterna had priority (thus reducing the
name blairi to a junior synonym of L. mexicana alterna). He
also reported on the first specimen of alterna from Durango,
suggesting that pattern element similarities between this specimen and the
single known example of L. leonis “suggests that leonis might
be part of the mexicana complex.” Tanzer’s discovery of extensive
pattern variation across Texas populations of alterna led him to
speculate about the potential for such phenomena elsewhere in the range of
L. mexicana, and that L. thayeri might be a blairi
phase of alterna. Although this suggestion might seem farfetched to
modern students of the group, Tanzer and his contemporaries were severely
hampered by the scarcity of specimens available for study. Interestingly,
given what we now know of pattern diversity in L. leonis, his comment
about the potential for polymorphism in other mexicana seems
wonderfully insightful.
1973 — Blaney,
R. M.
Lampropeltis Fitzinger. Catalogue of American Amphibians and Reptiles
(150):1–2. Offers support for Tanzer’s (1970) assessment that
Lampropeltis leonis (Günther) is a synonym of L. mexicana.
1978 — Williams,
K. L.
Systematics and Natural History of the
American Milk Snake, Lampropeltis triangulum. Milwaukee Public
Museum, Publications in Biology and Geology, Number 2. 258 pp. In this
published version of Williams’ Ph.D. dissertation, he relegates L.
ruthveni to the synonymy of L. triangulum arcifera. Clearly, he
was hampered by the paucity of preserved material from Jalisco, Michoacan,
and Querétaro, and by the fact that Blanchard’s type specimen of ruthveni
was represented only by a skin. Additionally, Williams seems to have been
influenced by H. M. Smith’s 1942 resurrection of L. t. arcifera, to
which Smith assigned various specimens from the full west-to-east extent of
the Mexican Plateau; some of these have subsequently been assigned to other
taxa (e.g., L. t. dixoni for TCWC 29504, from near Jalpan, Queretaro)
and others no doubt pertain to L. ruthveni. An accurate assessment of
“arcifera” has long been elusive, given the vagueness of the type
locality (“Mexique”), as the works of Smith and Williams illustrate.
Williams provides line drawings that depict head and midbody patterns of the
holotype of ruthveni.
1982 — Garstka,
W. R.
Systematics of the Mexicana species group of the colubrid genus
Lampropeltis, with an hypothesis [of] mimicry. Breviora (466):1–35. Garstka
reduces thayeri to the synonomy of L. mexicana, regards L.
alterna and L. mexicana as distinct species, and, importantly,
resurrects L. ruthveni from the synonomy of L. triangulum arcifera
(where it was buried by Williams, 1978) and includes it as a member of this
species group.
1998
— Hilken, G., and R. Schlepper.
Der
Lampropeltis mexicana-Komplex (Serpentes, Colubridae): naturgeschichte
und terrarienhaltung. Salamandra 34(2):97–124. Without presenting any new
data, authors regard this complex as comprised of L. mexicana (with 3
subspecies: mexicana, greeri, thayeri), L. ruthveni, and L.
alterna (with blairi and alterna as separate
subspecies—clearly in conflict with available evidence).
2002 — Bryson,
R. W., Jr.
Phylogenetic relationships of the Lampropeltis mexicana complex (Serpentes:
Colubridae) as inferred from mitochondrial DNA sequences. Master's thesis,
Sul Ross State University, Alpine, Texas. 53 pp. Bryson offers several
phylogenetic scenarios for L. alterna, mexicana, ruthveni, triangulum,
and the undescribed (at that time) webbi, based on mtDNA sequence
data. A favored tree is discussed in a biogeographic context.
2005 — Bryson,
R. W., Jr., J. R. Dixon, and D. Lazcano.
New species of Lampropeltis (Serpentes: Colubridae) from the Sierra
Madre Occidental, México. Journal of Herpetology 39(2):207–214. Original
description of Lampropeltis webbi from the Pacific versant of the
Sierra Madre Occidental near the Sinaloa//Durango border region. MtDNA
sequences and morphological characters are used to distinguish this form
from putative nearest relatives L. pyromelana and L. mexicana.
2007 — Bryson,
R. W., Jr., J. Pastorini, F. T. Burbrink, and M. R. J. Forstner.
A
phylogeny of the Lampropeltis mexicana complex (Serpentes: Colubridae)
based on mitochondrial DNA sequences suggests evidence for species-level
polyphyly within Lampropeltis.
Molecular
Phylogenetics and Evolution 43:674-684. Although the authors do not offer any taxonomic recommendations,
this paper adds to the growing evidence that
L. mexicana
and L. triangulum, as presently constituted, are not monophyletic
groups.
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