Mexican Transition Zone Research Articles

BIOGEOGRAPHIC AREAS AND TRANSITION ZONES OF LATIN AMERICA AND THE CARIBBEAN ISLANDS BASED ON PANBIOGEOGRAPHIC AND CLADISTIC ANALYSES OF THE ENTOMOFAUNA

Track and cladistic biogeographic analyses based on insect taxa are used as a framework to interpret patterns of the Latin American and Caribbean entomofauna by identifying biogeographic areas on the basis of endemicity and arranging them hierarchically in a system of regions, subregions, dominions, and provinces. The Nearctic region, inhabited by Holarctic insect taxa, comprises five provinces: California, Baja California, Sonora, Mexican Plateau, and Tamaulipas. The Mexican transition zone comprises five provinces: Sierra Madre Occidental, Sierra Madre Oriental, Transmexican Volcanic Belt, Balsas Basin, and Sierra Madre del Sur. The Neotropical region, which harbors many insect taxa with close relatives in the tropical areas of the Old World, comprises four subregions: Caribbean, Amazonian, Chacoan, and Parana. The South American transition zone comprises five provinces: North Andean Paramo, Coastal Peruvian Desert, Puna, Atacama, Prepuna, and Monte. The Andean region, which harbors insect taxa with close relatives in the Austral continents, comprises three subregions: Central Chilean, Subantarctic, and Patagonian.

Do fleas (Insecta: Siphonaptera) parallel their mammal host diversification in the Mexican transition zone?

AbstractAim The Mexican transition zone is a complex area where Neotropical and Nearctic biotic elements overlap. A previous study on mammal species has shown a great diversification in the area. We analyse the diversification of their flea species (Insecta: Siphonaptera), in order to determine if a diversification similar to their mammal host species has occurred.Location The area analysed corresponds to Mexico.Methods The panbiogeographical or track analysis was based on the comparison of the individual tracks of 112 species belonging to 48 genera and eight families of the order Siphonaptera. Generalized tracks were obtained based on the comparison of the individual tracks. Nodes were found in the areas where generalized tracks overlapped.Results Thirty‐four generalized tracks were obtained, distributed within the Mexican transition zone (20), the Nearctic region plus the Mexican transition zone (8), the Nearctic region (4) and the Neotropical region plus the Mexican transition zone (2). In the areas where they intersected, 26 nodes were identified: 23 in the Mexican transition zone and 3 in the Nearctic region.Main conclusions The nodes are concentrated in the Transmexican Volcanic Belt (14), Sierra Madre Oriental (5) and Sierra Madre del Sur (4) provinces of the Mexican transition zone. These results show a significant diversification of the flea taxa, in parallel with the diversification of their mammal hosts.

The diversification of Nearctic mammals in the Mexican transition zone

The boundary between the Nearctic and Neotropical regions has been delineated using different approaches, methods and taxa. Using a panbiogeographical approach, identification of nodes can help understand the dynamics and evolution of the boundary. We analysed the distribution patterns of 46 Mexican land mammal species belonging to the Nearctic biotic component and delineated generalized tracks and nodes, in order to determine the southernmost boundary of the Nearctic region in Mexico. We found six generalized tracks and nine nodes; the latter located largely in the Sierra Madre Oriental, Transmexican Volcanic Belt, Sierra Madre del Sur and Chiapas biogeographical provinces. The highlands of Chiapas were found to represent the southernmost area inhabited by Nearctic taxa. The other biogeographical provinces, together with the Sierra Madre Occidental and Balsas Basin provinces, represent the Mexican transition zone in the strict sense. Instead of a classic static boundary, this transition zone represents an evolutionarily ‘active’ zone, where several speciation events have taken place in the past.

Halffter’s Mexican Transition Zone, beetle generalized tracks, and geographical homology

AimHalffter’s Mexican Transition Zone is a complex area in which the Neotropical and Nearctic regions overlap. We test its existence and extension through a track analysis of beetle taxa, and discuss the implications of geographical homology.LocationThe area analysed corresponds to the Caribbean subregion, which occupies Mexico, Central America, north‐western South America, and the Western Indies.MethodsThe panbiogeographic or track analysis was based in the comparison of 134 individual tracks belonging to different beetle taxa (species and supraspecific groups). A Parsimony Analysis of Endemicity (PAE) was applied in order to classify the areas by their shared taxa according to the most parsimonious cladogram, and the nested sets of areas were represented as generalized tracks.ResultsTwo generalized tracks resulted: (1) northern generalized track: comprising the Sierra Madre Occidental, Sierra Madre Oriental, Transmexican Volcanic Belt, Balsas Basin and Sierra Madre del Sur biogeographic provinces; and (2) southern generalized track: comprising the Chiapas, Mexican Gulf, Mexican Pacific Coast and western Panamanian Isthmus biogeographic provinces.Main conclusionsThe generalized tracks obtained correspond broadly to Halffter’s Nearctic and Mesoamerican patterns, respectively; however, in contrast to Halffter’s Mesoamerican pattern, the southern generalized track extends further north through the lowlands of the Pacific and Mexican Gulf coasts.

Cladistic biogeography of the Mexican transition zone

AbstractBiogeographic relationships among nine montane areas of endemism across the transition zone between North and South America are analysed cladistically based on phylogenetic hypotheses of thirty‐three resident monophyletic taxa of insects, fish, reptiles, and plants.Areas of endemism include the Arizona mountains (AZ), Sonoran Desert (SD), Sierra Madre Occidental (OCC), southern Sierra Madre Occidental (SOC), Sierra Madre Oriental (ORI), Sierra Transvolcanica (TRAN), Sierra Madre del Sur (SUR), Chiapan‐Guatemalan Highlands (CGH), and Talamancan Cordillera (TC).Area relationships are summarized using Brooks Parsimony Analysis and Assumption 0, with the former resulting in more defensible biogeographic hypotheses.Areas of endemism are dividable into two monophyletic groups; a northern group including AZ, SD, OCC, and ORI, and a southern group consisting of TC, CGH, TRAN, SUR, and the isolated southern regions of the Sierra Madre Occidental (SOC).The northern set of areas are characterized by recent, probably Pleistocene, isolation and prevalent widespread species, whereas the southerly areas probably diverged after Pliocene closure of the Panamanian isthmus.The southern areas are redundantly represented on many of the taxon‐area cladograms by endemic species, indicative of much higher levels of endemism in the Sierra Transvolcanica and further south.Use of a general area cladogram in such a transition zone permits explicit exploration of biogeographic patterns and establishes a predictive framework for taxonomy and conservation prioritization.

Monografía de las especies mexicanas de Canthon del subgero Glaphyrocanthon (Coleoptera: Scarabaeidae: Scarabaeinae)

Este trabajo comprende la revisión monográfica de las especies mexicanas del subgénero Glaphyrocanthon (Scarabaeidae: Scarabaeinae: Canthon). Aunque en el conjunto de las Américas el subgénero nominotípico comprende más especies que Glaphyrocanthon, éste es el taxón supraespecífico más rico de los Canthonina de México (19 taxa contra 12 en el subgénero Canthon). Las especies mexicanas de Glaphyrocanthon no corresponden a una sola línea filética. En México están representados cuatro grupos de especies. De ellos, dos tienen su mayor diversificación en Sudamérica y las especies mexicanas son expansiones hacia el norte de líneas sudamericanas. Así, el grupo femoralis está representado en México por una sola especie, y el grupo subhyalinus por tres. En ambos casos se trata de formas asociadas a los bosques tropicales, a los excrementos de monos y que vuelan a considerable altura dentro del bosque. Canthon (Glaphyrocanthon) moroni conforma una tercera línea, de la cual no existe ninguna especie sudamericana próxima., Por último, el cuarto grupo: virldls, tiene una verdadera explosión de especiación (15 especies) en la Zona de Transición Mexicana. Es un grupo exclusivo y característico de esta zona. El trabajo Incluye una explicación de los caracteres morfológicos usados en claves y descripciones. Una clave para las especies y subespecies de Glaphyrocanthon de México, y una segunda clave para todas las especies del grupo subhyalinus (ambas claves se presentan en español e inglés). Un cuadro que resume los caracteres distintivos de las especies mexicanas de Glaphyrocanthon. Así como la diagnosis o descripción (en el caso de nuevos taxa) de los Glaphyrocanthon de México. En conjunto se estudiaron 20 taxa, de los cuales 10 son especies nuevas para la ciencia.

ORIGINS OF THE NORTH AMERICAN EPHEMEROPTERA FAUNA, ESPECIALLY THE LEPTOPHLEBIIDAE

AbstractThe complex origins of the North American Ephemeroptera fauna extended from the Lower Permian to the Recent. This paper discusses origins of North American genera of the cosmopolitan family Leptophlebiidae with a few examples from other mayfly families. The two extant subfamilies, Leptophlebiinae and Atalophlebiinae, probably evolved at least by the mid-Cretaceous, or about 100 million years before present. The primitive Leptophlebiinae are distributed throughout most of the Northern Hemisphere and the ancestors of the Leptophlebia–Paraleptophlebia complex within this subfamily dispersed widely by the North Atlantic route as early as the mid-Cretaceous and later probably by northern trans-Pacific dispersals through Beringia. The ancestors of Habrophlebia dispersed through the North Atlantic route at an early time, but the vicariant distribution of Habrophlebiodes in several areas of the Oriental Region and eastern North America correlates with the Arcto-Tertiary forest that covered most of the Northern Hemisphere including Beringia from the Early Tertiary into the Pleistocene. Within the nearly cosmopolitan Atalophlebiinae, Traverella is austral in origin and probably dispersed north through the Mexican Transition Zone during the mid-Tertiary as an ancient dispersal and then dispersed to its northern and eastern limits following the last Pleistocene deglaciation by way of the Missouri River tributaries. Thraulodes and Farrodes are both austral in origin and probably dispersed north through the Mexican Transition Zone during the Early Pleistocene as a relatively recent dispersal. The origins of Choroterpes sensu stricto and Neochoroterpes in North America are unknown. The mayfly fauna of the West Indies is Neotropical in origins, and no affinities between the West Indies and North America through Florida have ever been confirmed.

Biogeography of the Montane Entomofauna of Mexico and Central America

Faced with the challenge of writing a review on the distribution of insects in the mountains of Mexico and Central America (the Mexican Transition Zone), I found two possible alternatives: (a) to synthesize the latest publica­ tions or (b) to attempt to formulate a coherent theory that, although omitting some information and relevant references because of obvious space restric­ tions, would have the advantage of its consistency. I have followed the second alternative. I present a synthesis of information and hypotheses that may serve as a base to explain the distribution of montane insects in the Transition Zone. This is an exposition of essential features, not a summation of individual cases. I have defined (32) as the Mexican Transition Zone a complex and varied area in which the Neotropical and the Nearctic faunas overlap. This area includes part of the southwestern United States, all of Mexico, and a large part of Central America ex�ending to the Nicaraguan lowlands. The isthmus south of Lake Nicaragua (Costa Rica and Panama), although rich in ende­ misms, presents marked South American affinities and a Nearctic penetration similar to that of the northern part of South America. For these reasons I believe it is preferable not to consider this area as part of the Transition Zone. The physiography of the large Transition Zone is varied and complex as a result of the eventful geologic history that has prevailed since the Middle Cenozoic. The area's flora and fauna are exceptionally rich, owing on the one hand to the great variety of environments and ecological refuges available in

BIOSISTEMATICA DEL GENERO PETREJOIDES KUWERT (COLEOPTERA, LAMELLICORNIA, PASSALIDAE)

We studied the taxonomy of the Proculini genus Petrejoi- des Kuwert based on 600 specimens from dífferent mexican and central american locali- ties. We established the phyietic relationships of this genus within the tribe Proculini by defining 12 species, four of these species endemic to México are descríbed here. In the genus Petrejoides we distinguished three phyietic Unes. Orizabae line: composed by P. orizabae Kuwert, P. silváticas sp. nov. (MEXICO: Nuevo León; northern Sierra Madre Oriental, Chipinque-Cola de Caballo región), P. subrecticornis (Kuwert), P. jalapensis (Bates) and P. guatemalae Reyes-Castillo and Schuster. Laticornis Wne: oniy P. laticornis (Truqui). "Recticornis line: composed by P. recticornis (Burmeister), P. nebulosas sp. nov. MEXICO: Hidalgo: cloud forest in the vicinity of Tenango de Doria), P olmecae sp. nov. (MEXICO: Guerrero: wet slopes of the Sierra Madre del Sur, distributed through the cloud forest in the Omiltemi región), P. imbe- 2 Castillo, C. y P. Reyes-Castillo. Blosistemática de Petrejoides llis (Casey), P. mazatecus sp. nov. (MEXICO: Oaxaca: Sierra de Zongolica of the Sierra Madre Oriental, cloud forest in the vincity of Huautia de Jiménez), and P. tenuis Kuwert. We discussed the taxonomic characters and affinities of these three phyietic línes and we inelude an Identification key of the species. Every species is described or redescribed, discussing their varíations and affinities^ synonyms and com- ments, and are depicted for a better understanding of taxonomic characters used for description. Based on taxonomic affinities, ecological requirements and geographical distribution, we concluded that Petrejoides shows the Mesoamerican Mountain dispersal pattern with projections into Southern Central America. This is a typical montane taxa, preferently hygrophilous and completely sylvicolous. It shows a great diver- sification in the mountains located northwesterly to the Istmo de Tehuantepec, where the three phyietic lines oceur and is rich in endemic forms. In the Central American Nucleus, assumed as the origin area of Petrejoides, there is a low number of species which is, ap- parently, relatad with the diversification of Chondrocephalus these two genera have the highest affinities and share their rangas. In the Mexican Transition Zone speciation processes and the establishment of dispersal patterns of Petrejoides are highiy influenced by the distribu- tion and evolution of the cloud forest. The invasión of the mountains located to the north- west of the Istmo de Tehuantepec, probably was an event carried out in the earlier stages of the evolution of this genus. We assumed it based on the presence in this area of plesio- morphic and apomorphic species. opposed to the invasión of Southern Central America (Costa Rica, Panama) which has been a relatively recent event.