Type specimens of Elasmobranchii in the Museu de Zoologia da Universidade de São Paulo (MZUSP).

The type specimens of the subclass Elasmobranchii deposited in the Museu de Zoologia da Universidade de São Paulo are compiled in an annotated list, including updated measurements, verified collection data and recent photographs of holotypes and selected paratypes. Relevant information on the preservation condition of the specimens and their current taxonomic status are also provided. The collection holds a total of 135 lots of type specimens of elasmobranchs, three holotypes and seven paratypes in the division Selachii plus 16 holotypes, one neotype, and 108 paratypes in the division Batoidea (total specimen count: 137).

The history, importance and anatomy of the specimen that validated the giant Purussaurus brasiliensis Barbosa-Rodrigues 1892 (Crocodylia: Caimaninae).

The Solimões Formation is a southwest geological unit of the Brazilian Amazon, being well-known for the Cenozoic giant eusuchian fossils. Among the eight species of Crocodylia described for this formation, the alligatoroid Purussaurus brasiliensis is the best known worldwide due to its enormous size. The holotype was described in 1892 by Barbosa-Rodrigues, composed by a right hemimandible.

Comparative anatomy of the clasper of the subfamily Potamotrygoninae (Chondrichthyes: Myliobatiformes).

Claspers of stingrays (Myliobatiformes) are poorly documented in comparison to claspers of skates, with our knowledge restricted mainly to external morphological characters and skeletal components included in descriptions of new species; more encompassing morphological comparative analyses are lacking. Concerning potamotrygonins, clasper morphology has been described for a handful of species, but without elucidating their variation and systematic potential. The present article analyzed clasper structures in all genera of the subfamily Potamotrygoninae (Potamotrygon, Paratrygon, Plesiotrygon, and Heliotrygon), which were compared to the clasper of Styracura and some dasyatid genera.

A new subfamily, Styracurinae, and new genus, Styracura, for Himantura schmardae (Werner, 1904) and Himantura pacifica (Beebe & Tee-Van, 1941) (Chondrichthyes: Myliobatiformes).

A new subfamily (Styracurinae, subfam. nov.) and genus (Styracura, gen.