From fossilized imprints discovered in South Korea, paleontologists have reconstructed a remarkable narrative: that of a substantial, airborne reptile traversing the terrestrial landscape, seemingly in pursuit of smaller prey.
This fleeting moment has been preserved within a rock stratum for upwards of 106 million years. The smaller entity first entered the tableau at a leisurely pace – only to abruptly alter its trajectory and accelerate into a run.
The impetus for this sudden change appears evident: the distinctive impressions of a sizable pterosaur, exhibiting quadrupedal locomotion at a rapid pace, approach from a specific angle and closely trail the other organism.
Both sets of tracks subsequently recede from the confined temporal window offered by the stone slab, rendering the ultimate outcome of this ancient drama unknowable – though it is highly probable that the conclusion was unfavorable for the smaller creature.
“While the sole association of trackways does not constitute definitive proof of predation, the confluence of these evidential streams, particularly when considering the dimensions and ecological implications of the track-forming animal, could indeed indicate an interaction scenario,” the research team communicated in a publication detailing their findings.
The larger organism is unequivocally identified as a pterosaur – a category of flying reptiles that dominated the skies during the era of dinosaurs. However, comparative analyses with other fossilized footprints and skeletal remains indicate that it does not align perfectly with any cataloged species, leading the scientists to classify it as a novel genus and species, designated Jinjuichnus procerus.
This nomenclature is a composite, combining “Jinju” – the geographical area in South Korea where the fossil was unearthed – with ‘ichnus’, signifying ‘track’, a clear homage to the method of its discovery. The specific epithet ‘procerus’ is derived from Latin, meaning ‘elongated,’ a descriptor for the distinctive digits of its handprints.
Identification of the presumed quarry proves more challenging; however, the imprints appear consistent with those of a diminutive salamander, lizard, or crocodilian.
One might question the rationale for a flying creature engaging in terrestrial predation, yet this behavior is congruent with contemporary understanding of pterosaur ecology. It is widely theorized that many pterosaurs were capable of landing and ambulating adeptly on all fours, employing an almost simian gait.
These intervals between aerial excursions may have presented opportune moments for foraging, employing what researchers term a “terrestrial stalking” methodology. Pterosaurs are believed to have utilized this technique to hunt vertebrates such as lizards, mammals, fish, other pterosaurs, and even young or small dinosaurs, occupying an ecological niche comparable to that of modern storks.
Furthermore, their terrestrial movement could be surprisingly swift.
In this specific instance, the researchers estimate that the J. procerus was moving at approximately 2.9 kilometers (1.8 miles) per hour – not an all-out sprint, but certainly indicative of significant exertion for an animal primarily adapted for flight.
Although the researchers cannot definitively exclude the possibility that both organisms traversed the same site at different times without any encounter, the available evidence strongly suggests an interaction that was potentially lethal for one of the participants.
“Considering the following factors: (1) the probable temporal proximity of the two trackways; (2) the marked alteration in both velocity and direction of the smaller vertebrate trackway; (3) the apparent congruency of progression between the two trackways; (4) the inferred high speed of the pterosaur trackmaker; and (5) the paleoecological context of neoazhdarchians, an interaction between the two trackmakers appears more parsimonious than mere coincidental co-occurrence,” the researchers assert.
If indeed an interaction transpired, this discovery further reinforces the profound insights into the behavior of extinct fauna that fossil footprints can yield.
The findings of this investigation were disseminated in the academic journal Scientific Reports.
