MORPHOLOGICAL VARIATION AMONG THE APPENDICULAR BONES OF THE TITANOSAURIDAE (DINOSAURIA: SAUROPODA) FROM THE BAURU BASIN (UPPER CRETACEOUS) OF PEIRÓPOLIS (MG), BRAZIL
MARCELO N.F. TROTTA
Setor de Paleovertebrados, Departamento de Geologia e Paleontologia, Museu Nacional / UFRJ, Rio de Janeiro, RJ.
Presented by DIOGENES DE ALMEIDA CAMPOS
Several appendicular bones from the collection of the Departamento Nacional de Produção Mineral (DNPM/RJ) are being described for the first time. The bones were collected by L. I. Price between 1949 and 1974, and were unearthed from three main quarries: "Site 1 or Caieira'' (which also includes vertebral series and two sacra); "Serra da Galga'' and "Rodovia'' (Campos DA and Kellner AWA, 1999, Nat Sci Mus Mongr 15:143-166). None of these sites has yielded a single individual. The bones vary in size; most bear distinct morphological features, which allow their classification into different morphotypes. The scapulae display two morphotypes, based on the presence or absence of a medial prominence on the inner face. The biggest scapulae show further variation in the upper distal margin of the blade, which bears doubled expansions. The coracoids do not vary, but one displays an unique protuberance on its anterior upper corner. Based on overall shape and frontal profile, the sternal plates are either triangular or "T'' shaped. The ulnae display two different morphotypes, based on the presence or absence of an excavation on their distal articular areas. This excavation gives the distal surface of this element a reniform outline. The radii have been grouped into four morphotypes based on the overall robustness, shape of the distal articular facets, development of the proximal medial projection, and the presence of ridges running along the shaft. The pubes display three morphotypes based on the presence of a longitudinal ridge on the pubic apron and features of the iliac pedicle. The ischia display three morphotypes based on the presence or absence of a reentrance below the pubic pedicle and shape of the distal shaft. The femora may be either robust or slender. The fibulae display two morphotypes based on the presence or absence of an anterior trochanter and a medial oblique ridge. ( December 20, 2001 ).
Publication Dates
-
Publication in this collection
17 July 2002 -
Date of issue
June 2002
