| Zagaje Formation | |
| Type: | Geological formation |
| Age: | Latest Rhaetian-Lower Sinemurian~[1] |
| Period: | Hettangian |
| Prilithology: | Sandstone |
| Otherlithology: | Mudstone |
| Namedfor: | The Town of Zagaje near Gromadzice |
| Namedby: | Karaszewski (as an informal unit)[2] |
| Region: | Swietokrzyskie |
| Country: | |
| Coordinates: | 51.1°N 20.5°W |
| Paleocoordinates: | 43.1°N 18.8°W |
| Unitof: | Kamienna Group |
| Subunits: | Huta Mudstone Member |
| Underlies: |
|
| Overlies: | Unnamed Rhaetian Beds |
| Thickness: | 157.5 m |
| Area: | Polish epicontinental basin except of the Mazury region and Czêstochowa region. Reaches also into north Germany |
The Zagaje Formation is a Latest Triassic-Early Jurassic Epoch (Rhaetian-Sinemurian) geologic formation located mostly in Poland with layers also exposed in north Germany. This unit is known for its diverse Ichnofossil assemblages, with traces of invertebrates along vertebrate footprints, as well plants, large coal accumulations, invertebrate remains and ichnofossils.[4] The Zagaje Formation correlates with The lower part of the Höganäs Formation in Scania, as well the Munkerup Member and the Gassum Formation in Denmark.[1]
The Zagaje Formation is particularly visible in the Sołtyków region and is made mostly of Early Jurassic continental mudstone-sandstone deposits linked to the onset of "depositional sequence I". Its age is confirmed as mostly Early Hettangian through stratigraphic and paleontological analyses, including fossil flora and conchostraca findings. Sedimentological studies divide the Sołtyków profile into three parts: ephemeral reservoir deposits, floodplain and lacustrine sediments, and river channel deposits, highlighting dynamic depositional environments influenced by tectonic subsidence and varying hydrological conditions.[5]
Climate wise, the area was located back in the Hettangian around 45°N paleolatitude in Laurasia within a rise of 5–10°C above present, were it experienced significant climatic and environmental change related with sea-level fluctuations, manifested locally with a notorious retrogradational fluvial-lacustrine sedimentation, with evidence of a humid climate interspersed with drier seasons. Some plant fossils like Hirmeriella mark points of aridity on what was mostly a humid swampy alluvial-lacustrine habitat.[6] [7]
The Zagaje Formation’s deposits are know from both outcrops and borehole profiles that consist primarily of sandstones, mudstones, and interspersed coal and siderite layers. It represents a stratigraphic gap with the underlying Upper Triassic formations and is capped by a transgressive contact with the Skłoby Formation. This unit contains freshwater fauna and diverse trace fossils, including vertebrate tracks.[8] The paleoenvironment reflects a dynamic alluvial plain shaped predominantly by high-sinuosity stream processes, transitioning from earlier braided and low-sinuosity stream systems. This evolution is attributed to climatic changes, rising base levels, and decreasing geomorphological gradients. Observations, both from exposures and borehole data, highlight the dominance of avulsion processes, with several depositional subsystems identified. Facies with organic remains are diverse: riverbed biofacies, derived from meandering channels characterized by fining-upward sequences composed of channel lag deposits, point-bar sands, and finer overlying sediments. These deposits exhibit lateral accretion bedding and significant fossil bivalves and large-sized floated plant remains (stems and trunks of large plants) consistent with subaqueous dune migration within the channels; levee deposits derived from successive floods with scarce root traces, while plant remnants are common; Paleosoils with sparse traces of plant roots and remains of floating plants of highly variable size (mainly organic detritus, but also fragments of wood), fragments of bivalve shells and vertebrate remains (amniote bones, tracks, fish scales); the biofacies of the ephemeral water reservoir with plant remains, mainly horsetails, and fossils of insects, ostracods, and conchostraca; The pedogenic soil biofacies with remains of plant roots with preserved organic matter and rhizomes and stems in a living position; Floodplain biofacies with traces of numerous plant roots and plant macroremains, and remains of sedge stems preserved in a living position; Lake-marsh biofacies, dark, laminated mudstones with plant roots and coal, with few fossil bivalves, a large amount of organic matter in the form of plant detritus, and layers of coal and numerous finds of miospores and megaspores. The local presence of charcoal fragments and high concentrations of PAHs, along with possible burnt plants, provides evidence for wildfires in the region, that likely occurred near the surface with charred wood fragments were subsequently incorporated into sediments by river transport.[9]
The high presence of coprolites has allow also to stablish the tropic chain of the local biota, with a clear full ecosystemical substitution of the older Triassic archosaurs by Dinosaurs.[10] [11]
Several unname Ichnofossils are recovered at Soltyków, including conical domichnia (Conichnus?), bivalve straight to winding linear trails, smooth vertical and subvertical branching tunnels, knob-walled tunnels, mace-shaped or irregular ellipsoid chambers, etc.
| Genus | Species | Location | Material | Made By |
|---|---|---|---|---|
| Cruziana |
|
| Dwelling structures |
|
| Cochlichnus |
|
| Traces |
|
| Conichnus |
|
| Subcylindrical burrows |
|
| Diplichnites |
|
| Hypichnial trackway |
|
| Diplocraterion |
|
| U-Shaped Burrows |
|
| Imbrichnus |
|
| Burrows |
|
| Kouphichnium |
|
| V-shaped hypichnial marks |
|
| Palaeophycus |
|
| Straight or slightly curved burrows |
|
| Planolites |
|
| Horizontal burrows |
|
| Rusophycus |
|
| Resting Traces |
|
| Scolicia |
|
| Moving Traces |
|
| Scoyenia |
|
| Linear slender burrows |
|
| Skolithos |
|
| Sac/Bottle shaped burrows |
|
| Spongeliomorpha |
|
| Sac/Bottle shaped burrows |
|
Indeterminate gastropod egg capsules are know, similar to the ones recovered in the extant Neritina.[12] 4 unnamed morphotypes of freshwater bivalves of the family Unionidae are know.
| Genus | Species | Location | Material | Notes | Images |
|---|---|---|---|---|---|
| Anodonta[13] [14] |
|
| Isolated Shells | ||
| Calceoformites |
|
| Clog-shaped protrusions | Bivalve estabilization traces | |
| Cardinia |
|
| Isolated Shells | A Carditidae Bivalve. Indicator of oligohaline settings and found also on the younger Skłoby Formation | |
| Lockeia |
|
| Dwelling traces | Resting traces of Bivalves | |
| Ptychoplasma[15] |
|
| Locomotion trace | Gastropod Locomotion traces | |
| Scalichnus |
|
| Sac/Bottle shaped burrows | Escape structure of mud-dwelling bivalves | |
| Scolicia |
|
| Traces | Locomotion and feeding trace of gastropods | |
| Unio[16] |
|
| Isolated Shells | ||
| Viviparus[17] |
|
| Isolated Shells | ||
| Genus | Species | Stratigraphic position | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Bulbilimnadia |
|
| Valves | A freshwater Ostracodan of the family Bulbilimnadiidae | ||
| Darwinula |
|
| Valves | A freshwater Ostracodan of the family Darwinulidae | ||
| Euestheria[18] |
|
| Valves | A Freshwater Clam shrimp (Phyllopodan) of the family Lioestheriidae. | ||
| Isopodichnus |
|
| Hypichnial marks | Feeding and moving traces of phyllopod and notostracan crustaceans |
Radial chambers around large tunnels have been recovered, they may be arthropod burrows or traces of roots.[19] Large nest structures with septa, similar to nesting behaviour of insects like Cicadas are know.
| Genus | Species | Location | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Artematopodites[20] | A. ssp. |
| MPK 5/36, 39, 40 | A Coleopteran, member of the family Permosynidae | ||
| Blattodea | Indeterminate |
| MPK 5/54 | Indeterminate Blattodean remains | ||
| Blattulidae | Indeterminate |
| MPK 5/1 | Indeterminate Cockroach remains | ||
| Caraboidea | Indeterminate |
| MPK 5/12, 15 | Indeterminate Beetle remains | ||
| Coleoptera | Indeterminate |
| Isolated Wings | Indeterminate Beetle remains | ||
| Helminthoidichnites | cf. H. isp. |
| Gnawing traces | surficial gnawing traces made by insects | ||
| Hydrobiites | H. sp. |
| MPK 5/10, 13, 17, 22, 25, 33 | A Coleopteran, member of the family Permosynidae | ||
| Linckichnus | L. terebrans |
| Boring Traces | Detritivorous habitation dwellings or oviposition structures of insects in dead wood | ||
| Memptus | M. sp. |
| MPK 5/44 | A Coleopteran, Incertade sedis | ||
| Notocupes | N. sp. |
| MPK 5/6 | A Coleopteran, Incertade sedis | ||
| Odrowazicoris[21] | O. polonicus |
| MPK 5/2 | An Hemipteran, member of the family Belostomatidae | ||
| Polysitum | P.? sp. |
| MPK 5/14, 29 | A Coleopteran, Incertade sedis | ||
| Phoroschizidae | Indeterminate |
| MPK 5/4,5, 8, 20, 35 | Indeterminate Beetle remains | ||
| Xylonichnus | Cf.X. isp. |
| Boring Traces | Borings in the wood made probably by insect larvae |
Unidentified Actinopterygian fish scales and teeth were collected from clayish, organic-rich lake deposits, while some coprolites have been referred to Hybodontiform sharks.
| Genus | Species | Location | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Semionotus[22] | S. cf. bergeri | Czarniecka Góra | Single specimen | A Semionotiform bony fish of the family Semionotidae | ||
| Paleoniscidae | Indeterminate | Sołtyków | Scales & Teeth | Indeterminate Palaeonisciformes specimens |
| Genus | Species | Location | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Chelonipus | C. isp. | Sołtyków | Footprints | Turtle Tracks | ||
| Testudinata | Indeterminate | Sołtyków | Carapace Fragments | Unidentified Turtle remains, quoted to belong to a large sized taxon |
| Genus | Species | Location | Material | Notes | Images |
|---|---|---|---|---|---|
| Ameghinichnus | Cf.A. isp. | Sołtyków | Footprints | Small Synapsid tracks, likely from Mammaliaformes | |
| Brasilichnium | B. isp. | Sołtyków | Footprints | Small Synapsid tracks, likely from Mammaliaformes | |
| Dicynodontipus | D. isp. | Sołtyków | Footprints | Tracks referred to Eucynodonts, maybe Tritylodontidae | |
| Therapsipus | Cf.T. isp. | Sołtyków | Footprints | Tracks referred to Eucynodonts |
| Genus | Species | Location | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Batrachopus | B. isp. | Sołtyków | Footprints | Crocodrylomorph Tracks, likely of terrestrial taxa | ||
| Crocodylomorpha | Indeterminate | Sołtyków | Bones inside a large bromalite | An Indeterminate Crocodrylomorph, likely preyed on by a large Theropod | ||
| Crocodylomorpha | Indeterminate | Sołtyków | Footprints | Unnamed 3rd type of Footprint | ||
| Malutitetrapodiscus | Cf.M. isp. | Sołtyków | Footprints | Probably left by small terrestrial crocodylomorphs |
Some elliptical "post-egg" structures egshells & eggs with embryo remains have been referred to theropods, yet may also belong to Ornithischians.
| Genus | Species | Location | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Anchisauripus[23] [24] [25] |
| Sołtyków | Footprints | Adscribed to smal slender primitive predatory dinosaurs, related with genera such as Coelophysis | ||
| Eubrontes |
| Sołtyków | Footprints | Eubrontes is related to the Genus Dilophosaurus, representing a basal Neotheropods | ||
| Grallator[26] |
| Sołtyków | Footprints | Similar pes with Coelophysidae-alike dinosaurs, related with neotheropods such as Dracoraptor. | ||
| Kayentapus |
| Sołtyków | Footprints | Assumed to come from Genera similar to Sarcosaurus | ||
| Megalosauripus[28] | Cf.M. isp. | Sołtyków | Footprints | Large bodied taxa, maybe related with Sinosaurus. Among the largest early Jurassic theropod tracks worldwide. | ||
| Plesiornis |
| Sołtyków | Footprints | Theropod Tracks from small sized taxa with convergent features with latter Avians | ||
| Stenonyx[29] |
| Sołtyków | Footprints | Small Theropod tracks, likely from juveniles of larger taxa | ||
| Theropoda | Indeterminate |
|
| Some coprolites, referred to Theropods include plant material, probably ingested acidentally by drinking water. Others include large bone remains or fish scales. Teeth corroborate the presence of large taxa in the area. |
| Genus | Species | Location | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Megaloolithidae?[30] | Indeterminate | Sołtyków | Eggshells, eggs with embryo remains & spherical "post-egg" structures | Nesting structures & associated eggs referred to sauropods | ||
| Otozoum | Cf.O. isp. | Sołtyków | Footprints | Tracks referred to early quadrupedal or semibipedal sauropodomorphs | ||
| Parabrontopodus | P. isp. | Sołtyków | Footprints | Sauropod tracks, usually referred to taxa similar to Vulcanodon | ||
| Sauropodomorpha | Indeterminate | Hucisko |
| Indeterminate Sauropodomorph bones | ||
| Tetrasauropus | Cf.T. isp | Sołtyków | Footprints | Tracks referred to early quadrupedal or semibipedal sauropodomorphs |
| Genus | Species | Location | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Anomoepus |
| Sołtyków | Footprints | Tracks that resemble the feet of "Stormbergia" and various Genasauria of different sizes | ||
| Delatorrichnus |
| Sołtyków | Footprints | Tracks usually referred to Heterodontosauridae or similar taxa | ||
| Moyenisauropus[31] |
| Kontrewers | Footprints | Ttracks adscribed to basal Thyreophora, vinculated with genera such as Scelidosaurus |
In Palynology, the Zagaje Formation belongs to the Nathorstisporites hopliticus assemblage (Isoetales), indicating a spike in marshland and lacustrine settings.[32] The Sołtyków outcrop is dominated by Classopollis (Cheirolepidiaceae), Aratrisporites (Cycadidae), Concavisporites (Dipteridaceae) and Cyathidites (Cyatheaceae).
| Genus | Species | Stratigraphic position | Material | Notes | Images | |
|---|---|---|---|---|---|---|
| Aciphyllum |
|
| Cuticles | Affinities with Pinaceae inside Pinales. The oldest record of a Pinus-like needle in the fossil record | ||
| Brachyphyllum |
|
| Cuticles | Affinities with Cheirolepidiaceae or Araucariaceae inside Pinales | ||
| Caytonia[33] [34] |
|
| Reproductive structure | |||
| Czekanowskia |
|
| Branched Shoots | Affinities with the Czekanowskiales inside Ginkgoopsida. This Genus is related with relatively drier-cooler conditions. | ||
| Desmiophyllum |
|
| Cuticles | A possible Conifer leaf, recent finds of it associated with the cone genera Sphaerostrobus and Ourostrobus points to a coniferophyte affinity, maybe as a member of Palissyaceae.[35] | ||
| Dictyophyllum |
|
| Pinnae | Affinities with Dipteridaceae inside Gleicheniales. | ||
| Goepertella |
|
| Pinnae | Affinities with Dipteridaceae inside Gleicheniales | ||
| Hirmeriella[36] |
|
| Branched Shoots and reproductive cones | Affinities with the Cheirolepidiaceae inside Pinales. | ||
| Komlopteris |
|
| Cuticles | Affinities Corystospermaceae inside Corystospermales. | ||
| Matonia[37] |
|
| Pinnae | Affinities with Matoniaceae inside Gleicheniales | ||
| Neocalamites |
|
| Stems | Affinities with Calamitaceae inside Equisetopsida. A common horsetail on the Liassic of Europe. | ||
| Nilssonia |
|
| Cuticles | Affinities with Cycadeoidaceae in the Bennettitales or alternatively a member of Nilssoniales | ||
| Odrolepis |
|
| Complete Plants | Affinities with Lycopodiales | ||
| Otozamites |
|
| Leaflets | Affinities with Williamsoniaceae in the Bennettitales. | ||
| Pachypteris |
|
| Pinnae | Affinities Corystospermaceae inside Corystospermales. | ||
| Paracycas |
|
| Leaflets | Affinities with Cycadales in the Cycadopsida. | ||
| Piroconites |
|
| Reproductive structure | Affinities with Gnetales, | ||
| Phlebopteris |
|
| Cuticles | Affinities with Matoniaceae in the Gleicheniales. | ||
| Podozamites |
|
| Branched shoots | Affinities with Krassiloviaceae inside Voltziales | ||
| Pseudotorellia |
|
| Cuticles | Affinities with the Pseudotorelliaceae inside Ginkgoopsida. | ||
| Pterophyllum |
|
| Leaflets | Affinities with Williamsoniaceae in the Bennettitales. | ||
| Ptilozamites |
|
| Cuticles | Affinities Corystospermaceae inside Corystospermales. | ||
| Sagenopteris |
|
| Leaves | |||
| Schmeissneria[38] |
|
| Reproductive structure | Affinities with Ginkgoopsida or with Angiosperm-convergent Gimnosperms | ||
| Swedenborgia |
|
| Branched Shoots | Affinities with Krassiloviaceae inside Voltziales. | ||
| Thaumatopteris |
|
| Pinnae | Affinities with Dipteridaceae inside Gleicheniales | ||
| Todites |
|
| Pinnae | Affinities with Osmundaceae in the Osmundales. |
Poland
Germany