Comparison of footprint length to pace length (FL/PL) ratios of Limiavipedidae, theropod traces, and traces of Mesozoic, Cenozoic, and extant birds.

Comparing the footprint length (FL) to pace length (PL) ratios (FL/PL) of Wupus agilis to the large avian trace Limiavipes curriei (Limiavipedidae) and to small- (Irenichnites isp.) medium- (Columbosauripus isp., Magnoavipes isp.) and large-sized (Irenesauripus isp.) theropod ichnotaxa, and traces of large Cenozoic, and extant avians. Wupus agilis and Limiavipes curriei have a larger FL/PL than do small theropod traces of comparable size and those of medium-sized theropods. Columbosauripus isp. has the largest mean FL/PL of the analyzed theropod traces. The FL/PL of Wupus agilis and Limiavipes curriei have the most overlap with the FL/PL of avian traces. This indicates that, relative to the length of the track-maker’s foot, the track-makers of both Wupus agilis and Limiavipes curriei are either taking relatively shorter steps than similarly-sized theropods, or have relatively shorter legs than do similarly-sized theropods.
Comparison of footprint length to pace length (FL/PL) ratios of Limiavipedidae, theropod traces, and traces of Mesozoic, Cenozoic, and extant birds.