# Precipice Sandstone

The Precipice Sandstone an Early Jurassic (Sinemurian to early Pliensbachian, with possible Hettangian levels) geologic formation of the Surat Basin in New South Wales and Queensland, eastern Australia, know due to the presence of abundant vertebrate remains & tracks. This unit includes the previously described Razorback beds. This unit represents a major, almost primary, source of hydrocarbons in the region, with a Potential CO2 reservoir of up to 70m. It was deposited on top of older sediments, like Bowen Basin units, in an unconformable manner, resting along the eastern basin margin and the Back Creek Group in the southern Comet Platform, while in other areas it directly overlies the Triassic Moolayember Formation & Callide Coal Measures, being deposited in a comparatively stable basin. Isopach maps of the Precipice Sandstone indicate two distinct areas of sediment accumulation, suggesting two separate depocentres filled from different source regions during the Sinemurian, with the Thomson orogeny and New England Orogen hinterlands as possible ones. This unit represented a fluvial-palustrine-lacustrine braided channel north-flowing succession, that seem to have debouch into a shallow restricted tidal/wave influenced marine embayment, marked at areas like Woleebee Creek. Paleoenvironment-wise, it represents a hinterland rich in vegetation, hinting at wet environments like swamps, where agglutinated foraminifera suggests marine flooding and drier conditions or the encroachment of seawater onto coastal areas.

## Fireclay Caverns

The Fireclay Caverns were excavated by the Mount Morgan Mine to provide clay for its brickworks resulting in very large openings that measure between 4–12 metres in height from the cave floor. Excavation of the caverns ceased when the mine brickworks were decommissioned in the early 1900s. Erosion revealed dinosaur footprints (preserved as infills) being discovered in 1954. To date, nine different ceiling sections of the Fireclay Caverns have been recognised as containing dinosaur footprints. These have been dated to the Early Jurassic (Sinemurian) ~195 million years ago. Walkways and stairs had been constructed in 2010 to provide access to the dinosaur footprints as part of the mine site tours. The site was closed to access in 2011 due to ceiling erosion posing a significant risk to public safety.
The Fireclay Caverns were excavated to supply clay to brickworks of the Mount Morgan Mine. Clay was mined from within the caverns by pick and shovel, then transferred by underground rail to a brickworks lower in the Mount Morgan Mine site. Excavation from the caverns ceased when their clay was no longer required by the mine. After cavern excavations ceased, clay progressively fell from the cavern ceilings, revealing rock ceilings above. In 1954, HRE Staines, a Mount Morgan Limited geologist, identified dinosaur footprints in the rock ceilings. Over 300 such footprints have been identified on the cavern ceilings dated to the Early Jurassic (Sinemurian) ~195 million years ago. 2024 represents the 70th anniversary of when Ross Staines published Australia's first dinosaur trackway-consisting of four footprints. To celebrate, previously unpublished archival photographs (c. 1954) enabled a re-examination of Staines' original trackway, from which two additional footprints were revealed. Analyses indicated the trackmaker exhibited a walking gait, initially walking at ~3.8 km/h and then slowed to 1.8 km/h in association with a slight turn in direction.
After cavern excavations ceased, a colony of bent-wing bats began inhabiting the caverns. The sections of the caverns containing the bats are inaccessible to protect the bat habitat.

## Biota
### Invertebrates

| Genus | Species | Type | Location | Material | Origin | Notes | Images |
| Asterosoma | A. isp. | Fodinichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Radiating bulb-like swelling burrows | Annelid worm, vermiform organism | Freshwater/brackish burrow-like ichnofossils | |
| Conichnus | C. isp. | Domichnia Cubichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | trails | Gastropods | Freshwater/brackish fillings-like ichnofossils | |
| Cylindrichnus | C. isp. | Domichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Long, subconical, weakly curved burrows | Anemones Polychaete worms | Freshwater/brackish burrow-like ichnofossils | |
| Diplocraterion | D. parallelum | Domichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | U-shaped burrows | Polychaeta annelids (Axiothella, Abarenicola and Scolecolepis) Sipunculans (Sipunculus) Enteropneustans (Balanoglossus) Echiurans (Urechis). | Vertical, U-shaped, single-spreite Burrows; unidirectional or bidirectional spreite, generally continuous, rarely discontinuous. Most Diplocraterion show only protrusive spreiten, like the local ones, produced under predominantly erosive conditions where the organism was constantly burrowing deeper into the substrate as sediment was eroded from the top. | Diplocraterion parallelum diagram |
| Helminthopsis | H. isp. | Fodinichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Simple, unbranched, horizontal cylinder traces | Polychaetes Priapulids | Saltwater/brackish burrow-like ichnofossils. | Example of Helminthopsis fossil |
| Lockeia | L. amygdaloides L. isp. | Cubichnia Domichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Dwelling traces | Bivalves | Marine, brackish or freshwater resting traces of Bivalves. | |
| Naktodemasis | N. isp. | Fodinichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Straight to sinuous, unlined and unbranched burrows | Soil bugs Cicada nymphs Scarabaeid beetle larvae | Freshwater/Terrestrial burrow-like ichnofossils. | |
| Palaeophycus | P. tubularis | Domichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Straight or gently curved tubular burrows. | Polychaetes Semiaquatic Insects (Orthoptera and Hemiptera) Semiaquatic and non-aquatic Beetles. | Freshwater/brackish burrow-like ichnofossils. | Example of Palaeophycus fossil |
| Phycosiphon | P. isp. | Fodinichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Irregularly meandering burrows | Vermiform Animals | Freshwater burrow-like ichnofossils. | |
| Planolites | P. montanus P. beverleyensis P. isp. | Pascichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Cylindrical or elliptical curved/tortuous trace fossils | Polychaetes Insects | Freshwater/brackish burrow-like ichnofossils. Planolites is really common in all types of the Ciechocinek Formation deposits. It is referred to vermiform deposit-feeders, mainly Polychaetes, producing active Fodinichnia. It is controversial, since is considered a strictly a junior synonym of Palaeophycus. | Example of Planolites fossil |
| Scolicia | S. isp. | Cubichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Symmetrical trail or burrow | Gastropods | Freshwater/brackish trail-like ichnofossils | Scolicia trails |
| Skolithos | S. isp. | Domichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Cylindrical strands with branches | Polychaetes Phoronidans | Brackish trace ichnofossils. Interpreted as dwelling structures of vermiform animals, more concretely the Domichnion of a suspension-feeding Worm or Phoronidan. | |
| Siphonichnus | S. ophthalmoides | Domichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Cylindrical strands with branches | Polychaetes Phoronidans | Brackish trace ichnofossils. Interpreted as dwelling structures of vermiform animals, more concretely the Domichnion of a suspension-feeding Worm or Phoronidan. | |
| Taenidium | T. serpentinum T. isp. | Fodinichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Unlined meniscate burrows | Deposit-feeding Sipuncula Polychaetes Phoronidans | Freshwater/Blackish burrow-like ichnofossils. Taenidium is a meniscate backfill structure, usually considered to be produced by an animal progressing axially through the sediment and depositing alternating packets of differently constituted sediment behind it as it moves forward. | |
| Thalassinoides | T. isp. | Tubular Fodinichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Tubular Burrows | Thalassinidea Several Crustaceans (Anomura, Decapoda) Annelids (Polychaeta Sipuncula Dipnoi | Burrow-like ichnofossils. Large burrow-systems consisting of smooth-walled, essentially cylindrical components. Common sedimentary features are Thalassinoides trace fossils in the fissile marlstone to claystone intervals | Thalassinoides burrowing structures, with modern related fauna, showing the ecological convergence and the variety of animals that left this Ichnogenus. |
| Teichichnus | T. isp. | Fodinichnia | Chinchilla 4 Borehole Condabri MB9-H Borehole Kenya East GW7 Borehole Moonie 31 Borehole Moonie 34 Borehole Reedy Creek MB3-H Borehole Roma 8 Borehole Taroom 17 Borehole West Wandoan 1 Borehole Woleebee Creek GW4 Borehole | Vertical to oblique, unbranched or branched, elongated to arcuate spreite burrow | Polychaetes Dwelling Echiurans Dwelling Holothurians. | Saltwater/brackish burrow-like ichnofossils. The overall morphology and details of the burrows, in comparison with modern analogues and neoichnological experiments, suggest Echiurans (spoon worms) or Holothurians (sea cucumbers) with a combined suspension- and deposit-feeding behaviour as potential producers. | Teichichnus burrows |

### Vertebrata

| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Anomoepodidae | Indeterminate | Biloela | Lower Member | Footprints | ornithischian footprints, unassigned to any concrete ichnogenus, but with resemblance with Anomoepodidae | Small ornithischians similar to Lesothosaurus may have left these footprints |
| Anomoepus | A. scambus A. ispp. | Callide Basin Carnarvon Gorge Fireclay Caverns Mount Morgan | Lower Member | Footprints | Ornithischian Footprints, originally suggested as quadrupedal theropod tracks, latter identified as of Ornithischian origin. Up to 130 tracks & 4 short trackways are know. | |
| Eubrontes | E. isp. | Fireclay Caverns | Lower Member | Footprints | Medium-sized Theropod Footprints. Currently represent the largest of the prints at Mount Morgan | |
| Grallator | G. isp. | Fireclay Caverns | Lower Member | Footprints | Small-sized Theropod Footprints | |
| Plesiosauria | Indeterminate | Mount Morgan | Razorback Beds | QM F3983-QM F5500, single disarticulated skeleton preserved as natural moulds | A Freshwater Plesiosaur that cannot be confidently attributed to any particular plesiosaurian clade | |
| Steropoides | S?. isp | Biloela tracksite | Lower Member | Footprints | Small-sized Ornithischian Footprints | |
| Theropodipedia | Indeterminate | Callide Mine Mount Morgan | Lower Member | Footprints | Possible theropod footprints, unassigned to any concrete ichnogenus. One morphotype includes large tridactyl prints, up to 24 cm. | Small theropods similar to Procompsognathus may have left these footprints |
| Theropodipedia | "Indet. 2" | Fireclay Caverns | Lower Member | Footprints | Possible theropod footprints, unassigned to any concrete ichnogenus. One morphotype includes large tridactyl prints, up to 24 cm. | Small theropods similar to Procompsognathus may have left these footprints |
| Theropodipedia | "Indet. 3" | Fireclay Caverns | Lower Member | Footprints | Possible theropod footprints, unassigned to any concrete ichnogenus. One morphotype includes large tridactyl prints, up to 24 cm. | Small theropods similar to Procompsognathus may have left these footprints |
| Wintonopus | W. isp. | Fireclay Caverns | Lower Member | Footprints | Small-sized Ornithischian Footprints | |

### Bryophyta

| Genus | Species | Stratigraphic position | Material | Notes | Images |
| Annulispora | A. folliculosa A. microannulata | Razorback Beds | Spores | Incertae sedis; affinities with Bryophyta. | |
| Cingutriletes | C. spp. | Razorback Beds | Spores | Incertae sedis; affinities with Bryophyta. | |
| Distalanulisporites | D. punctus D. verrucosus | Razorback Beds | Spores | Affinities with the family Sphagnaceae in the Sphagnopsida. | |
| Foraminisporis | F. spp. | Razorback Beds | Spores | Affinities with the family Notothyladaceae in the Anthocerotopsida. | |
| Nevesisporites | N. vallatus | Razorback Beds | Spores | Incertae sedis; affinities with Bryophyta. This spore is found in Jurassic sediments associated with the polar regions. | |
| Polycingulatisporites | P. crenulatus P. densatus P. mooniensis | Razorback Beds | Spores | Affinities with the family Notothyladaceae in the Anthocerotopsida. Hornwort spores. | Extant Notothylas specimens |
| Stereisporites | S. antiquasporites S. perforatus | Razorback Beds | Spores | Affinities with the family Sphagnaceae in the Sphagnopsida. "Peat moss" spores, related to genera such as Sphagnum that can store large amounts of water. | Extant Sphagnum specimens |

### Lycophyta

| Genus | Species | Stratigraphic position | Material | Notes | Images |
| Apiculatisporis | A. spp. | Razorback Beds | Spores | Incertae sedis; affinities with Lycopodiopsida | |
| Lycopodiumsporites | L. austroclavatidites L. rosewoodensis | Razorback Beds | Spores | Affinities with the family Lycopodiaceae in the Lycopodiopsida. Lycopod spores, related to herbaceous to arbustive flora common in humid environments. | Extant Lycopodium specimens |
| Neoraistrickia | N. truncata N. spp. | Razorback Beds | Spores | Affinities with the Selaginellaceae in the Lycopsida. | |

### Pteridophyta

| Genus | Species | Stratigraphic position | Material | Notes | Images |
| Calamospora | C. spp. | Razorback Beds | Spores | Affinities with the Calamitaceae in the Equisetales. Horsetails are herbaceous flora found in humid environments and are flooding-tolerant. In the sections of the formation such as Korsodde, this genus has small peaks in abundance in the layers where more Equisetites stems are found. | Reconstruction of the genus Calamites, found associated with Calamospora |

### Pteridophyta

| Genus | Species | Stratigraphic position | Material | Notes | Images |
| Annulispora | A. microannulata A. folliculosa | Razorback Beds | Spores | Affinities with the genus Saccoloma, type representative of the family Saccolomataceae. This fern spore resembles those of the living genus Saccoloma, being probably from a pantropical genus found in wet, shaded forest areas. | Extant Saccoloma specimens; Annulispora probably comes from similar genera or maybe a species in the genus |
| Baculatisporites | B. comaumensis | Razorback Beds | Spores | Affinities with the family Osmundaceae in the Polypodiopsida. Near fluvial current ferns, related to the modern Osmunda regalis. | Extant Osmunda specimens; Baculatisporites and Todisporites probably come from similar genera or maybe a species from the genus |
| Camarozonosporites | C. spp. | Razorback Beds | Spores | Incertae sedis; affinities with the Pteridophyta | |
| Cyathidites | C. australis C. minor | Razorback Beds | Spores | Affinities with the family Cyatheaceae in the Cyatheales. Arboreal fern spores. | Extant Cyathea |
| Densoisporites | D. spp | Razorback Beds | Spores | Incertae sedis; affinities with the Pteridophyta | |
| Dictyophyllidites | D. mortoni | Razorback Beds | Spores | Affinities with the family Matoniaceae in the Gleicheniales. | |
| Duplexisporites | D. gyratus | Razorback Beds | Spores | Incertae sedis; affinities with the Pteridophyta | |
| Foraminisporis | F. tribulosus | Razorback Beds | Spores | Incertae sedis; affinities with the Pteridophyta | |
| Foveosporites | F. sp. | Razorback Beds | Spores | Incertae sedis; affinities with the Pteridophyta | |
| Heliosporites | H. spp | Razorback Beds | Spores | Incertae sedis; affinities with the Pteridophyta | |
| Indusiisporites | I. parvisaccatus | Razorback Beds | Spores | Incertae sedis; affinities with the Pteridophyta | |
| Osmundacidites | O. wellmanii | Razorback Beds | Spores | Affinities with the family Osmundaceae in the Polypodiopsida. Near fluvial current ferns, related to the modern Osmunda regalis. | |
| Rugulatisporites | R. spp. | Razorback Beds | Spores | Affinities with the family Osmundaceae in the Polypodiopsida. Near fluvial current ferns, related to the modern Osmunda regalis. | |

### Peltaspermales

| Genus | Species | Stratigraphic position | Material | Notes | Images |
| Alisporites | A. australis A. lowoodensis A. sp. | Razorback Beds | Pollen | Affinities with the families Peltaspermaceae, Corystospermaceae or Umkomasiaceae in the Peltaspermales. Pollen of uncertain provenance that can be derived from any of the members of the Peltaspermales. The lack of distinctive characters and poor conservation make this pollen difficult to classify. Arboreal to arbustive seed ferns. | |
| Vitreisporites | V. contectus V. pallidus | Razorback Beds | Pollen | From the family Caytoniaceae in the Caytoniales. Caytoniaceae are a complex group of Mesozoic fossil floras that may be related to both Peltaspermales and Ginkgoaceae. | |

### Conifers

| Genus | Species | Stratigraphic position | Material | Notes | Images |
| Classopollis | C. classoides C. simplex | Razorback Beds | Pollen | Affinities with the Hirmeriellaceae in the Pinopsida. | |
| Perinopollenites | P. sp. | Razorback Beds | Pollen | Affinities with the family Cupressaceae in the Pinopsida. Pollen that resembles that of extant genera such as the genus Actinostrobus and Austrocedrus, probably derived from dry environments. | Extant Austrocedrus |
| Podosporites | P. spp. | Razorback Beds | Pollen | Affinities with the family Podocarpaceae. Pollen from diverse types of Podocarpaceous conifers, that include morphotypes similar to the low arbustive Microcachrys and the medium arbustive Lepidothamnus, likely linked with Upland settings | Extant Microcachrys |