Isisfordia molnari: A new species of Crocodyliform from the Middle Cretaceous of New South Wales.

The Crocodyliforms were the only group of Crocodylomorphs to survive the End Triassic Extinction event. The group includes all modern Crocodylians, but also a number of extinct groups, such as the Dog-like Peirosaurians, the short-snouted, long-legged Notosuchins, the fully marine Metriorhynchids, and the Dyrosaurids, a diverse group which survived till the Eocene. These Crocodyliforms were abundant in the Mesozoic of most of the Southern Hemisphere, but are startlingly absent from the Australian continent, where only a single species has been described, Isisfordia duncani, from the Middle Cretaceous of Queensland, a species thought to be closely related to, but not placed within, the still extant Crocodylians.

In a paper published in the journal PeerJ on 21 June 2019, Lachlan Hart and Phil Bell of the Palaeoscience Research Centre at the University of New England, Elizabeth Smith of the Australian Opal Centre, and Steven Salisbury of the School of Biological Sciences at the University of Queensland describe a second species of Isisfordia from two opalised bone fragments from mines in the Lightning Ridge area of New South Wales and Queensland.

Opal is an amorphous form of silica containing as much as 21% water, It is made up of tiny spheroids of crystalline silica some 150 to 300 nm in diameter, with random alignments to one another. Light passing through these crystaloids is refracted as by a prism, leading to the 'opalescent' sheen which gives the mineral its value. Opal is formed by water percolating through silica rocks, where it dissolves some of the mineral forming a silica-rich solution. This can accumulate in any cracks or gaps in the rock, where if it reaches a high enough concentration it can precipitate out as opal. The Cretaceous Griman Creek Formation of northern New South Wales and southern Queensland is noted for the occurrence of opalised vertebrate fossils, replacement fossils formed when opal forms in gaps in the rock left by the dissolution of bone or earlier replacement material. However, these are rare and are not always spotted in areas where the opal is mined using mechanised equipment, which also means that the material that is recovered is often fragmented.

The new species is named Isisfordia molnari, in honour of Ralph Molnar, for his work on Crocodylomorphs from the Griman Creek Formation, and Australian vertebrate palaeontology in general. The species is described from two specimens, a braincase recovered from a mine in 2000 and donated to the Australian Museum by opal miners Peter and Lisa Caroll, and a partial maxilla (upper jawbone) extracted in 1914 and donated to the Australian Museum by Colonel Reuter Emerich Roth. The precise locations where these specimens were found is unclear, though the jaw was probably from Three Mile Field, close to the town of Lightning Ridge, and the braincase is probably from Coocoran Fields, 30 -40 km to the west.

Isisfordia molnari, maxillary fragment from the Griman Creek Formation. (A) medial, (B) lateral, (C) palatal views. Arrows indicate rostral end. Scale bars equal 10 mm. Abbreviations: ag, alveolar groove; is, interalveolar septa; ms, medial `shelf'; pp, palatal process. Hart in Hart et al. (2019).

Isisfordia molnari is differentiated from Isisfordia duncani on the basis of the shape of the pariedal bones (the bones which form the side and roof of the skull in Humans), which are flat in Isisfordia molnari and have ridges on them in Isisfordia duncani, and the shape and spacing of the tooth sockets, which are rounded in Isisfordia duncani  and oval in Isisfordia molnari.

Reconstruction of Isisfordia molnari in life, swimming next to a wading Sauropod. José Vitor Silva in Hart et al. (2019).

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Fostoria dhimbangunmal: An opalised Iguanodontian from the Cretaceous of New South Wales.

Opal is an amorphous form of silica containing as much as 21% water, It is made up of tiny spheroids of crystalline silica some 150 to 300 nm in diameter, with random alignments to one another. Light passing through these crystaloids is refracted as by a prism, leading to the 'opalescent' sheen which gives the mineral its value. Opal is formed by water percolating through silica rocks, where it dissolves some of the mineral forming a silica-rich solution. This can accumulate in any cracks or gaps in the rock, where if it reaches a high enough concentration it can precipitate out as opal. The Cretaceous Griman Creek Formation of northern New South Wales and southern Queensland is noted for the occurrence of opalisedvertebrate fossils, replacement fossils formed when opal forms in gaps in the rock left by the dissolution of bone or earlier replacement material. However, these are rare and are not always spotted in areas where the opal is mined using mechanised equipment, which also means that the material that is recovered is often fragmented.

In a paper published in the Journal of Vertebrate Paleontology on 3 June 2019, Phil Bell, Tom Brougham, Matthew Herne, and Timothy Frauenfelder of the University of New England, and Elizabeth Smith of the Australian Opal Centre describe a new species of non-Hadrosaurid Iguanodontian Dinosaur from a bone-bed within the Griman Creek Formation exposed in a mine targeting the Sheepyard Opal Field, approximately 40 km southwest of the town of Lightning Ridge in central northern New South Wales.

To date only a single Iguanodontian Dinosaur has been described from Australia, the possible Rhabdodontomorph Muttaburrasaurus langdoni from the Early Cretaceous Mackunda Formation in central Queensland, though a number of trackways attributed to Iguanodontians are known from Cretaceous Australian deposits, suggesting more members of the group were present.

The new species is named Fostoria dhimbangunmal, where 'Fostoria' honours Robert Foster, the miner who discovered the bone bed from which the material assigned to the species came, and 'dhimbangunmal' means 'Sheep Yard' in the language of the Yuwaalaraay, Yuwaalayaay, and Gamilaraay peoples. The material comes from a bone bed which was partially excavated for its opal content before the fossil nature of the material was recognised. The material is therefore somewhat fragmented, though it appears to have come from at least four disarticulated skeletons.

Chronostratigraphy and map of the Surat Basin in Australia showing the approximate extent of the Eromanga Sea (blue) during the Albian. Lightning Ridge is indicated by an open square in the main image. Inset showing location of the ‘Sheepyard’ opal field near Lightning Ridge (star). Fostoria dhimbangunmal comes from a monodominant bone bed (triangle) in the uppermost part (Cenomanian) of the Griman Creek Formation. Bell et al. (2019).

The material referred to the species comprises a partial skull roof and braincase, right quadrate, four partial and complete scapulae (three of which are left, with the single right specimen being different in size to any of the left scapulae, hence the estimate that there are at least four individuals present), a left humerus, a probable left radius, a right ischium, portions of left and right femora, a left tibia, a probable partial left fibula, and a number of partial metatarsals, pedal phalanges and vertebrae.

Fostoria dhimbangunmal, forelimb and girdle elements. Left scapula in (A) lateral; (B) medial; and (C) anterior views. Left humerus in (D) posterior; (E) medial; and (F) anterior views. (?) Left radius in (G) medial; (H) lateral; and (I) proximal views. Abbreviations: ac, acromion ridge; c, sutural contact for coracoid; df, deltoid fossa; dp, deltopectoral crest; gl, glenoid fossa; gr, medial groove associated with coracoid foramen; mr, medial ridge; r, ridge; sg, supraglenoid fossa. Scale bars equal 2 cm. Bell et al. (2019).

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Queensland miner killed in trench collapse.

A sixty-two-year-old miner has been found dead following a the collapse of an exploration trench at a mine in Opalton, Queensland, on Saturday 22 October 2016. Sid Cuddy was reported missing after a friend visited the site where he was operating at about 4.00 pm local time. The location is described as being extremely remote, being about 150 km southwest of Winton and about 300 km west of Longreach, and it took police and firefighters six hours to reach the site, and a further three hours to clear the trench and find Mr Cuddy's body.

Sid Cuddy (62), who died in a collapse at an exploration trench at an opal mine in Opalton, Queensland, on 22 October 2016. The Courier Mail.

Opal is an amorphous form of silica containing as much as 21% water, It is made up of tiny spheroids of crystalline silica some 150 to 300 nm in diameter, with random alignments to one another. Light passing through these crystaloids is refracted as by a prism, leading to the 'opalescent' sheen which gives the mineral its value. Opal is formed by water percolating through silica rocks, where it desolves some of the mineral forming a silica-rich solution. This can accumulate in any cracks or gaps in the rock, where if it reaches a high enough concentration it can precipitate out as opal.

Opal beds in Queensland are found largely in exposures of the Cretaceous Winton Formation, an iron rich sandstone laid down in a shallow inland sea (the Etomanga Sea) that covered parts of Queensland and central Australia during the Early Cretaceous. which extends from Hungerford on the New South Wakes border northwest to the area around Kynuna, a distance of over 1000 kilometres. The opal here is typically found in cracks in ironstone concretions (themselves formed by precipitation from water that has accumulated iron as it peculated through the feruginous sandstone), and is commonly called 'boulder opal'.

These fields have been worked since the 1870s, with the bulk of the mining done by small, artisanal miners who sink shallow trenches into the sandstone looking for opal-bearing boulders. The Opalton deposits were among the first opal fields discovered in Australia, and as well as still supporting a mining industry, are now a thriving tourist attraction.

Mr Cuddy is described as having been a highly experienced miner, always willing to help other less experienced prospectors. The cause of the collapse that killed him is as yet unknown.

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