Reclassification of vertebrate trackways from the Permian of Scotland and related forms from Arizona and Germany

Abstract

The large number of ichnospecies in Permian vertebrate ichnology literature is often a result of a failure to recognize substrate or gait-controlled variations in trackway morphology. Additionally, regional studies were often performed in isolation from studies in other areas. Nomenclatural priority applies to the names first assigned to trackways from the Corncockle and Locharbriggs Sandstone Formations (Permian) of Dumfries and Galloway, Scotland. Only one ichnogenus, Chelichnus, and four ichnospecies are recognized here and all had been identified in the studies of Jardine in 1850 and 1853. Chelichnus represents tetrapod trackways with rounded manus and pes impressions, subequal in size with up to 5 short digits where preservation is complete. The normal trackway pattern shows a pes pace angulation of up to 90° with the manus and pes being impressed close together or possibly with a slight overlap of the manus by the pes. Chelichnus bucklandi shows a pes size of 10 to 25 mm, C. duncani shows a pes size of 25 to 75 mm, C. gigas shows a pes size of 75 to 125 mm, and C. titan displays a pes size exceeding 125 mm in length. This restriction to four ichnospecies is more in accord with the low faunal diversity to be expected from an eolian environment of Late Permian age than was the former taxonomic classification. The Permian ichnofaunas of the Coconino Sandstone of Arizona and the Cornberger Sandstein of Germany are also composed largely of these four ichnospecies.

Formation and Taphonomy of Human Footprints in Microbial Mats of Present-Day Tidal-flat Environments: Implications for the Study of Fossil Footprints

“…Identification of true tracks is further complicated in the fossil record where footprints undergo different stages of taphonomy and are at different stages within the diagenetic sequence of development. This corroborates Allen (1997) who stated that only a very small proportion of the tracks in a given area are capable of yielding diagnostic taxonomic information about the animals that made them, and McKeever and Haubold (1996) who showed that many Permian ichnogenera are nothing more than substrate or behavioral variants of the same trackmaker.…”

Range of Experimental Dinosaur (Hypsilophodon foxii) Footprints Due to Variation in Sand Consistency: How Wet Was the Track?

“…It is particularly important, therefore, to identify if and how foot anatomy has been obscured by sediment conditions and to exclude those preservational variants from ichnotaxonomic nomenclature. Indeed, the relatively large number of Late Permian vertebrate ichnospecies from the Corncockle and Locharbriggs Sandstone Formations of Dumfries and Galloway, Scotland, reflects the failure to recognize substrate variations in the development of track morphology (McKeever and Haubold, 1996). Many tracks of Chelichnus lyelli are of comparable size range to C. bucklandi, which those authors considered to be substrate-controlled variants of the latter.…”

Chirotherium barthii Kaup 1835 from the Triassic of the Isle of Arran, Scotland

“…Carboniferous, Permian and Jurassic tracks and trackways are well known from the rocks of Scotland (Clark 2001, Clark and Jewkes 2000, Clark and Barco Rodriguez 1998, Hopkins 1999, McKeever 1994, McKeever and Haubold 1996. Tracks from the Triassic are, however, poorly represented in Scotland despite a number of tetrapod remains being found from the Lower Norian Lossiemouth Sandstone Formation (Benton and Walker 1985).…”