Dinosaurs in the Year of Darwin

Abstract

This special issue of The Anatomical Record explores the recent advances in the functional morphology and paleobiology of dinosaurs. Although Darwin did not study dinosaurs because paleontology was in its infancy a century and half ago, he considered both paleontology and anatomy as essential subjects for establishing the validity of evolution. The study of dinosaurs constitutes a vigorous subdiscipline within vertebrate paleontology, and anatomists and evolutionary functional morphologists constitute an especially creative subgroup within dinosaur paleontology. The collection of 17 papers presented in this issue encompass cranial anatomy, postcranial anatomy, and paleobiology of dinosaurs and other archosaurs. Soft tissue subjects include studies of brain structure, jaw adductor muscles, and keratinous appendages of the skull. Taxonomically, it includes four papers with a focus on theropods, including Tyrannosaurus, five papers dealing with ceratopsians, three papers on hadrosaurs, and one on ankylosaurs. Modern anatomical techniques such as CT scanning, finite element analysis, and high resolution histology are emphasized. The visual presentation of results of these studies is spectacular. Results include the first-ever life history table of a plant-eating dinosaur; a determination of the head orientation of Tyrannosaurus and its relatives based on interpretation of the semicircular canals. The claws of Velociraptor appear to best adapted for tree climbing, but not for horrific predatory activities. Pachyrhinosaurus evidently used its massive head for head butting. The tail club of the armored dinosaur Euoplocephalus had the structural integrity to be used as a weapon. The pages abound with insights such as these. Dinosaurs once dead for millions of years live again! Anat Rec, 292:1240Rec, 292: -1245Rec, 292: , 2009. V V C 2009 Wiley-Liss, Inc.

A Probable Neoceratopsian Manus Track from the Nanushuk Formation (Albian, Northern Alaska)

“…-longer toe impressions -Digit I most prominent versity and evolutionary transitions (Dodson, 2009 et al, 2000). It seems easier to envision an increase in body size within a temporally correlative taxonomic group than to invoke a significant range extension for a more derived, younger-occurring taxonomic group.…”

A Jugal in the Rough: The Evolutionary Importance of the Zygoma

“…That would be great.” Peter, is, and was, always the kind and perceptive teacher who could see when a student was lost. He guided me through Anatomy lab at Yale, and has since guided thousands more as a revered Professor of Veterinary Anatomy and Vertebrate Paleontology at Penn, not to mention the world's leading expert on those funky dinosaurs with horns on their heads (see Dodson, ; Laitman, ).…”

“…As anyone who has spent even a few moments with Peter knows, get him in room with dinosaurs, particularly ceratopsians (the horned dudes, he's their king!) and he's gone (see Dodson, .) But, I was in heaven!…”

The Anatomical Record Continues Our Special Issue, “Understanding the Zygoma,” Now Exploring the Extraordinary Twists and Turns of Its Evolutionary Journey in Our First “Act II” of a Special Issue

“…Their compendia detailed reviews and cutting‐edge science exploring many aspects of the zygoma's growth, development, variation, and experimental manipulations in a range of species. This, the second‐part, delves into questions that relate to evolutionary and comparative aspects of the vertebrate skull, long a favored topic of our august journal (see, for example, many papers in Laitman ; Ross, ; Marquez, ; Dodson, ; Van Valkenburgh et al, ). Delving deeper into our archives, one will find: comments on the evolutionary/systematic importance of facial bones in the comparative, osteological study of rails and cranes by Shufeldt (); by the extraordinary, and often under‐appreciated osteologist, Bruno Oetteking in his insights on the evolution of the human zygoma (Oetteking, ); work by Allis () assessing ancestral homologies to the squamosal bone in fish; beautiful, and detailed, comparative anatomy of the facial musculature and zygomatic arch of the orang by Sullivan and Osgood (); and by Shanker, on the skulls of extant and fossil turtles, with insights on jugal evolution among these groups and reptiles in general (Shanker, ).…”