title: Morphometric analysis of the Rio Apaporis Caiman (Reptilia, Crocodylia, Alligatoridae).
abstract: Caiman crocodilus apaporiensis has been considered by several authors as an extreme of morphological variation within the Caiman crocodilus complex. Here, we evaluate its position in the Caiman crocodilus complex morphospace using morphological traits from head shape. We examined the holotype and seventeen paratypes of Caiman crocodilus apaporiensis Medem 1955 deposited at the Field Museum of Natural History. We performed multivariate morphometric analyses: principal component analysis (PCA) and discriminant function analysis (DFA), based on 21 cranial traits of of C. c. apaporiensis, C. yacare and the C. crocodilus complex (C. c. chiapasius, C. c. fuscus andC. c. crocodilus). We find a notable separation of C.c. apaporiensis from C. yacare and C. crocodilus complex in the morphospace. We suggest that geographic isolation might have driven this morphological separation from the C. crocodilus complex, but further analysis are necessary to confirm whether these differences are related with genetic differentiation within the complex. In addition, we suggest that environmental heterogeneity might drive the evolution of independent lineages within the C. crocodilus complex.
authors.affiliation: Centro del Cambio Global y la Sustentabilidad en el Sureste A.C., Centenario del Instituto Juárez s/n, 86080 Villahermosa, Tabasco, México; Email: unknown.
authors.forename: Armando H
authors.initials: AH
authors.lastname: Escobedo-Galván
authors.affiliation: Laboratorio de Análisis Espaciales, Instituto de Biología, Universidad Nacional Autónoma de México, 04360 México D.F., México; Email: unknown.
authors.forename: Julián A
authors.initials: JA
authors.lastname: Velasco
authors.affiliation: Proyecto de Conservación de Aguas y Tierras - ProCAT Colombia/Internacional, Carrera 13 # 96-05, Of. 205, Bogotá, Colombia & Instituto de Ecología, Universidad Nacional Autónoma de México, 04360 México D.F., México; Email: unknown.
authors.forename: José F
authors.initials: JF
authors.lastname: González-Maya
authors.affiliation: Division of Amphibians and Reptiles, Field Museum of Natural History, 1400 S. Lake Shore Drive, Chicago, IL 60605-2496 USA; Email: unknown.
authors.forename: Alan
authors.initials: A
authors.lastname: Resetar
mesh_terms: D000489:Alligators and Crocodiles / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development; D063147:Animal Distribution; D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D049628:Body Size; D005260:Female; D008297:Male; D009929:Organ Size