The folklore of footprints in stone: From classical antiquity to the present

Since classical times and earlier, footprints in stone have intrigued humanity. Sometimes the supposed footprints were mere indentations produced by the chances of erosion; sometimes they were invertebrate fossils; and sometimes they were faked; but quite often they were the tracks of extinct creatures. The interpretations resulting from observations of these phenomena included legends of gods, heroes and saints: but, on occasion, the envisioning of the track‐maker was remarkably accurate. This account of the folklore of footprints surveys legends from Europe, North and South America, Africa and Australia; it concludes with the beginning of their scientific observation.     

Endo‐ and epilithic faunal succession in a Pliocene–Pleistocene cave on Rhodes,Greece: record of a transgression

A fossil cave and associated sediments and fossil fauna located on the Greek island of Rhodes in the eastern Aegean Sea is reported here, and the depositional history discussed. The sediments were deposited during the late Pliocene, in the interstitial space between basement boulders of up to 1500 tons. The depositional history of the cave comprises eight stages. From initial flooding, the basin experienced a continuous transgression with sea‐level rise in excess of 500 m, followed by a rapid, forced regression of similar magnitude. The recognition of a succession of fossil communities illustrates this transgression, with a seemingly abrupt shift from endolithic to epilithic biota dominance late in the transgressive cycle. The communities recording the increasing water depth from 0 to >150 m are: The Gatrochaenolithes torpedo (bivalve boring) and Entobia gonioides (sponge boring) ichnocoenosis, with peak distribution between 0 and 1 m water depth; the E. gonioides – E. magna ichnocoenosis, with 1–5 m depth peak distribution; the exclusive E. magna ichnocoenosis, with 5–40 m depth peak distribution; and the E. gigantea ichnocoenosis, with a peak distribution approaching 150–200 m. Below this depth, an epilithic community without boring organisms takes over, characterized by the calcareous sponge Merlia cf. normani, and the inarticulate brachiopod Novocrania turbinata. Simultaneously with the succession of the endo‐ and epilithic cave wall fossil communities, skeletal calcarenite accumulated on the cave floor; the erosional remnants of this sediment are insufficient to further expand the overall transgression–regression model.     

Giant Eocene bird footprints from Northwest Washington,USA

Abstract. Tridactyl bird footprints preserved in Lower Eocene sandstone of the Chuckanut Formation in Whatcom County, Washington, USA, were made by a species of giant ground bird that walked along the subtropical lowland riverbank. The morphology and age of the tracks suggest the track maker was Diatryma (? = Gastornis). Although these birds have long been considered to be predators or scavengers, the absence of raptor‐like claws supports earlier suggestions that they were herbivores. The Chuckanut tracks are herein named as Rivavipes giganteus ichnogenus and ichnospecies nov., inferred to belong to the extinct family Gastornithidae.     

Ichnofossil tiering analysis of a rhythmically bedded chalk-marl sequence in the Upper Cretaceous of Alabama

Ichnofossils are typically well expressed at bed transitions within rhythmically bedded marine sequences. This is because most discrete biogenic structures therein are actively or passively filled with sediment derived wholly or partly from overlying layers; hence they contrast sharply with ambient sediments. These bed transitions, or 'piped zones', provide the opportunity to assess the nature of infaunal tiering using two different approaches: (1) cross-cutting relationships among recurring ichnotaxa; and (2) apparent maximum penetration depths of piped-zone ichnofossils below their intervals of origination (primary strata). Both approaches were applied to piped zones at chalk-marl and marl-chalk transitions within the rhythmically bedded Upper Cretaceous (Campanian) Demopolis Chalk of western Alabama. Quantitative analysis of cross-cutting relationships indicates the existence of a deep Chondrites tier, a shallow Thalassinoides tier, and a diverse intermediate tier characterized by Anconichnus, Planolites, Taenidium, Teichichnus , and Zoophycos. Analyses of penetration depths similarly document the presence of a deep Chondrites tier but indicate that the Thalassinoides producer occupied the same tier as the tracemakers of the remaining five ichnotaxa. The latter approach, which should be broadly applicable to heterolithic sequences of various sorts, appears to yield a more accurate picture of tiering because it provides a more direct reading of the depths of activity of tracemakers within a substrate, and because results are less likely to be influenced by behavioral factors (e.g., phobotaxis and preferential sediment exploitation) or other parameters (e.g., burrow size differences) that can impact cross-cutting relationships. Results of both approaches indicate that the tiering structure in pelagic carbonate substrates may not be as organized or complex as indicated by previous qualitative analyses of cross-cutting relationships in analogous chalk sequences.     

The Ichnofossils of the Triassic Hope Bay Formation,Trinity Peninsula Group,Antarctic Peninsula

The Triassic Hope Bay Formation (Trinity Peninsula Group) includes a diverse ichnocoenosis in the Puerto Moro succession (Hope Bay, Antarctic Peninsula). The Hope Bay Formation is a thick turbidite succession with a minimum vertical exposure of 533 meters along the Hope Bay coast. The rocks are locally affected by contact metamorphism related to later arc magmatism. The ichnofossils are found mainly in thick- and thin-bedded sandstone-mudstone facies composed of a monotonous repetition of sandstone-mudstone cycles. The sandstones are usually medium grained, massive or parallel laminated; the mudstones are massive and rarely laminated. In the fine-grained rocks, mainly the mudstones, there are distinct densities of bioturbation, and at least six patterns were observed. The following ichnogenera were recognized: Arenicolites Salter 1857, Lophoctenium Richter 1850, Taenidium Heer 1877, Palaeophycus Hall 1847, Phycosiphon von Fischer-Ooster 1858 and Rhizocorallium Zenker 1836. All appear to be feeding-traces. The trace fossil assemblages occur mainly in black mudstones rich in organic material that suggest a low oxygen environment. The stratigraphic interval in which they occur is interpreted as progradational supra-fan lobes with channel fill and levee deposits. The thin-bedded turbidite and mudstone lithofacies, where the ichnofossils are abundant, is interpreted as a distal fan turbidite or levee deposit related to a long-term channel fill. This study is the first significant report of trace fossils in the Hope Bay Formation.     

Neoichnological activities of endobenthic invertebrates in downdrift coastal Ganges delta complex,India: Their significance in trace fossil interpretations and paleoshoreline reconstructions

Neoichnological studies of the downdrift coastal Ganges deltaic region (Ganges Delta Complex) indicate the nature and environmental zonation of the lebensspuren of common endobenthic invertebrates dominated by the brachyuran amphibious crab Family Ocypodidae (Ocypode spp., Ilyaplax pusillus and Uca marionis) and are utilized to interpret analogous trace fossils and paleoshoreline environments. The polycha‐ete Diopatra cuprea, the gastropods Turritella spp., Tele‐scopium telescopium and Cerithidea obtusum, some bivalves and the boring crab Charybdis rostrata also produce diagnostic lebensspuren.

The measured ichnoprofiles reveal the development of coast parallel Uca ‐Turritella (backswamps and salt‐marshes; 1 type burrows), Ocypode ‐ Ilyoplax (backshore to foreshore), Charybdis rostrata (foreshore relict woodground; boring structures), polychaete (middle‐lower foreshore; current ‐ oriented agglutinated burrows) and bivalve ‐ gastropod (lower foreshore; trails) ichnozones. Ocypode ‐ Ilyoplax, irrespective of ontogenic stages and sex, produce I, J, U, Y, and multibranched Y ‐ shaped burrows (juvenile ‐ old in backshore versus young ‐ adult in foreshore) in an orderly fashion. Their burrow density and diversity attain a maximum in backshore and upper foreshore respectively. Exceptionally, high burrow populations produce network burrow systems in the backshore. Juvenile pelletal designs (upper foreshore) and general landward burrow inclination are conspicuous.

The described lebensspuren, having a wide range of ancient analogues, provide supportive evidence in the identification of lithified crab burrows, paleoshoreline environments and paleosealevel fluctuations.     

FIRST OCCURRENCE OF FOOTPRINTS OF LARGE THERAPSIDS FROM THE UPPER PERMIAN OF EUROPEAN RUSSIA

Abstract:  Large footprints of terrestrial tetrapods have been found in the Cis-Urals region of European Russia. The footprint horizon is in Late Permian (Changhsingian) deposits of the Vyatkian Gorizont (uppermost Tatarian) approximately 50 m below the local Permian/Triassic boundary. Seventeen randomly orientated footprints were excavated and are referred to the ichnospecies Brontopus giganteus . The footprints were emplaced in a reddish-brown mudstone that was deposited from suspension beneath shallow ponded water in a floodplain environment. They were subsequently cast by the base of the overlying fine-grained sandstone, which was deposited from a sheet-flood event. The footprints were produced by a large therapsid, possibly a dinocephalian, but more probably a dicynodont, and represent the first ichnological record of the Therapsida from the Upper Permian of Russia.     

New Miocene scarabeid and hymenopterous nests and early miocene (santacrucian) paleoenvironments,patagonian Argentina

Three new trace fossils are described from Miocene paleosols of southern Argentina. Celliforma pinturensis, n. ichnosp. and Celliforma rosellii, n. ichnosp. are interpreted as cells of digging bees, possibly Anthophoridae, and Coprinisphaerafrenguellii, n. ichnosp. are brood balls of dung‐beetles. Both burrowing bees and dung‐beetles are common nesters in relatively open areas, confirming previous reconstructions of the paleoenvironment of the Pinturas Formation. A brief review of scarabeid and bee fossil nests from South America is presented, and we propose that constructed nests have a higher preservation potential than excavated nests. This fact explains their more common occurrences as trace fossils in paleosols. A new ethological category, calichnia, is proposed for hymenopterous and coleopterous traces, in which adult individuals make nests exclusively for larvae.     

Obituary: Ron K. Pickerill (1947–2018)

Recently discovered tracks in alluvial sediments of the Late Paleocene Bullion Creek Formation of western North Dakota have been identified as belonging to the large eusuchian crocodile Borealosuchus formidabilis and an associated small arthropod. They are described as two new ichnotaxa. The first of these, Borealosuchipus hanksi igen. et isp. nov., is based on a partly complete trackway having fore- and hind-footprints as well as body marks preserved in hyporelief. These tracks are directly associated with numerous body fossils including articulated bones which provide strong implications for their probable origin. The second specimen, Koupichnium pentapodus isp. nov., is founded on a trackway of a small invertebrate in which a series of five pairs of footprints are arranged along a midline drag mark which is continuous throughout the length of its trackway. This trackway shares features with other fossils as well as living arthropod trackways in which four small feet and a larger posterior hind “pusher” foot are present. The two described new ichnotaxa represent the first recognized tracks from the Wannagan Creek local fauna.     

Small shelly fossils and trace fossils near the Precambrian-Cambrian boundary in the Yukon Territory, Canada

In the past an ‘explosion’ in diversity and abundance of small shelly fossils and of trace fossils has served to mark the base of the Cambrian. However, no evidence has been presented to prove that the ‘explosions’ of the two groups were synchronous. We describe small shelly fossils and trace fossils from the same phosphatic limestone beds that indicate that the two events were separate in time. The small shelly fossils are Anabarites trisulcatus, Hyolithellus cf. H. isiticus, Microcornus? sp., Protohertzina anabarica, P. unguliformis, P. sp. A, Pseudorthotheca sp. A, Rushtonia? sp. A, four types of tuberculate plates and one type of reticulate plate. These fossils represent a restricted, ‘pre-explosion’ fauna and are assigned to the Anabarites-Circotheca-Protohertzina Assemblage Zone, an uppermost Precambrian zone in the Meishucun Stage, Yunnan Province, China. A point at the top of this zone has received strong international endorsement for future designation as the base of the Cambrian. Associated with the small shelly fossils are the trace fossils Cruziana sp. A, Cruziana? sp. B, Rusophycus sp. A, Palaeophycus rubdark and arthropod scratch marks. If found in isolation, this trace fossil assemblage would be considered as post-Precambrian because it includes large, highly organized arthropod traces that are traditionally accepted as occurring above the trace fossil ‘explosion’. We therefore conclude that the trace fossil ‘explosion’ predates the small shelly fossil ‘explosion’. If the proposed location of the base of the Cambrian in Yunnan is accepted, the small shelly fossil ‘explosion’ concept and its relationship to the boundary would not be greatly modified. The trace fossil ‘explosion’, however, would no longer indicate the base of the Cambrian and the ranges of some trace fossils would be extended into the Precambrian.