Abstract
Isolated theropod dinosaur tracks were first collected in Hungary from Hettangian (Lower Jurassic) beds of the Mecsek Coal Formation in 1966 and described as Komlosaurus carbonis CitationKordos, 1983. Our study is based on newly collected material from additional track-bearing beds. The description of the two largest preserved surfaces containing a total of 102 tracks that can be referred to as 21 trackways is provided here. This represents the first attempt to measure, map and compare the tracks of these bipedal, functionally tridactyl dinosaurs in several associated trackways. Significant morphological variability can be observed (e.g., depth, presence or absence of a metatarsal impression, digit length, digit divarication angle) that is explained by differences in physical parameters of the substrate. The mean of pes length is 16.3 cm in tracksite PB1 and 19.9 cm in tracksite PB2. Stride length of trackways usually ranges between 120 and 170 cm; pace angulation is 160–175°. The speed of the trackmaker is calculated to range between 6 and 14 km/h. Imprints are diagnosed by a pes length/width ratio lower than 2.0; metatarsal pads and hallux impressions are frequent. Based on the similarity of several morphological characters, the herein described tracks are referred to the ichnotaxon Komlosaurus carbonis, which is clearly distinct from Grallator and Kayentapus.
ACKNOWLEDGMENTS
The field crew led by György Szakmány and Sándor Józsa (Eötvös University of Budapest) discovered and collected the tracksites in the Pécsbánya open pit mine in 1988. Ágoston Nagy, Zsolt Pataki and other geology students at that time contributed to this study with great efforts. They carried out the original mapping and basic documentation. The Mecsek Coal Mines Company generously supported excavation and field work. Lajos Németh provided expert help and guidance and made available a geological profile of the mine site. Collecting was aided and partially sponsored by the Hungarian Natural History Museum. Additional financial help was provided by the Geological Research Group of the Hungarian Academy of Sciences–Eötvös University. Numerous people are thanked for their help in assembling the slab PB1, a project supported by the Eötvös University and the Hungarian Natural History Museum. Assembly of slab PB2 was made possible through a grant from the Hungarian Cultural Fund (NKA). Zsuzsanna Molnár assisted in data entry and processing. We thank István Szente for useful consultations. Constructive and thoughtful reviews by Hendrik Klein, John Foster and Spencer Lucas greatly improved the manuscript. A.Ő. acknowledges the support of a Bolyai Scholarship from the Hungarian Academy of Sciences. This study was financially supported by the Hungarian Scientific Research Fund (grants OTKA PD 73021 and K72633). This is MTA–MTM Paleo contribution 124.