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Malformed trilobite specimens present important insight into understanding how this extinct arthropod group recovered from developmental or moulting malfunctions, pathologies, and injuries. Previously documented examples of malformed trilobite specimens are often considered in isolation, with few studies reporting on multiple malformations in the same species. Here we report malformed specimens of the ellipsocephaloid trilobite Estaingia bilobata from the Emu Bay Shale Konservat-Lagerstätte (Cambrian Series 2, Stage 4) on Kangaroo Island, South Australia. Ten malformed specimens exhibiting injuries, pathologies, and a range of teratologies are documented. Furthermore, five examples of mangled exoskeletons are presented, indicative of predation on E. bilobata. Considering the position of malformed and normal specimens of E. bilobata in bivariate space, we demonstrate that the majority of malformed specimens cluster among the larger individuals. Such specimens may exemplify larger forms successfully escaping predation attempts, but could equally represent individuals exhibiting old injuries that were made during earlier (smaller) growth stages that have healed through subsequent moulting events. The available evidence from the Emu Bay Shale suggests that this small, extremely abundant trilobite likely played an important role in the structure of the local ecosystem, occupying a low trophic level and being preyed upon by multiple durophagous arthropods. Furthermore, the scarcity of malformed E. bilobata specimens demonstrates how rarely injuries, developmental malfunctions, and pathological infestations occurred within the species. [ABSTRACT FROM AUTHOR]

Studies that reveal detailed information about trilobite growth, particularly early developmental stages, are crucial for improving our understanding of the phylogenetic relationships within this iconic group of fossil arthropods. Here we document an essentially complete ontogeny of the trilobite Redlichia cf. versabunda from the Cambrian Series 2 (late Stage 4) Ramsay Limestone of Yorke Peninsula in South Australia, including some of the best-preserved protaspides (the earliest biomineralized trilobite larval stage) known for any Cambrian trilobite. These protaspid stages exhibit similar morphological characteristics to many other taxa within the Suborder Redlichiina, especially to closely related species such as Metaredlichia cylindrica from the early Cambrian period of China. Morphological patterns observed across early developmental stages of different groups within the Order Redlichiida are discussed. Although redlichiine protaspides exhibit similar overall morphologies, certain ontogenetic characters within this suborder have potential phylogenetic signal, with different superfamilies characterized by unique trait combinations in these early growth stages. [ABSTRACT FROM AUTHOR]

Despite 70 years of study, Dickinsonia remains one of the Ediacara biota's most enigmatic taxa with both morphological characters and phylogenetic affinities still debated. A large population of relatively small Dickinsonia costata present on a semi-contiguous surface from the Crisp Gorge fossil locality in the Flinders Ranges (South Australia) provides an opportunity to investigate this taxon in its juvenile form. This population supports earlier findings that suggest D. costata's early growth was isometric, based on the relationship between measured variables of length and width. The number of body units increases with length, but at a decreasing rate. A correlation between a previously described physical feature, present as a shrinkage rim partially surrounding some specimens and a novel, raised lip in some specimens, suggests that both features may have been the result of a physical contraction in response to the burial process, rather than due to a gradual loss of mass during early diagenesis. A marked protuberance in 15% of the population is also noted in limited specimens within the South Australian Museum collections and appears to be present only in juvenile D. costata. Both the abundance and narrow size range of this population support the notion that Dickinsonia was a hardy opportunist, capable of rapid establishment and growth on relatively immature textured organic-mat substrates. [ABSTRACT FROM AUTHOR]

A new euarthropod from the Emu Bay Shale (Cambrian Series 2, Stage 4) on Kangaroo Island, South Australia, is a rare component of this Konservat-Lagerstätte. The two known specimens of Eozetetes gemmelli gen. et sp. nov., in combination, depict a non-biomineralized euarthropod with a relatively short cephalic shield lacking dorsal eyes and bearing a flagelliform antenna, 18 trunk segments with broad tergopleurae and paired axial nodes/carinae, and an elongate, styliform tailspine. The new species compares most closely with taxa in the putative clade Vicissicaudata, which groups Aglaspidida, Cheloniellida and Xenopoda. A ring-like terminal tergite in E. gemmelli corresponds to the caudal tergite in cheloniellids and xenopodans. Incorporating Eozetetes into recent character sets for Cambrian euarthropods supports close affinities to either Emeraldella or to aglaspidids, but several plesiomorphic character states are inconsistent with membership in Aglaspidida sensu stricto. Eozetetes is among the earliest of various Cambrian taxa informally referred to as ‘aglaspidid-like euarthropods’. [ABSTRACT FROM PUBLISHER]

New and previously described "Sphinctozoan" taxa have been collected from six different localities in northern Spain, all of them dated as Late Carboniferous, from Moskovian to Kasimovian in age. The sphinctozoans in the collection are all assigned to the Demospongiae: a new species of polyglomerate type, Cystothalamia vandegraaffi n. sp., and known species Amblysiphonella barroisi Steinmann, 1882, Amblysiphonella carbonaria (Steinmann, 1882), Discosiphonella mammilosa (King, 1943), Discosiphonella major (Van de Graaff, 1969), and Sollasia ostiolata Steinmann, 1882. Some of these specimens present interesting paleoecological features, such as the use of a piece of calcareous algae as a hard substrate in a soft muddy bottom and a possible branching pattern determined by photophilic or negative geotaxic growth. [ABSTRACT FROM AUTHOR]

New collections of fossil sponges have been recovered from Devonian to Upper Carboniferous sections of Spain. These include two new hexactinellids from Devonian rocks of northwestern Spain: the small globular protospongiid Iberospongia globulara new genus and species, and the much larger, bowl-shaped, pelicaspongiid Asturiaspongia aqualiforma new genus and species. The three specimens of Asturiaspongia n. gen. were collected from the calcareous member of the Aguión Formation, of late Emsian age, at Arnao Beach, Asturias. This member has been interpreted as a developing patch reef. The single specimen of Iberospongia n. gen. was collected from late Zlichovian (Emsian) beds of the Cortés Member of the Abadía Formation, near Polentinos, Palencia. These beds represent the beginning of the transition to deeper water that took place during the Emsian and which lasted throughout the Devonian. Lower Carboniferous sponges have been collected from southern Spain. The hexactinellid Estrellaspongia irregulara new genus and species, is a thick-walled, basin-shaped pelicaspongiid with irregular, branched, inhalant canals and coarser irregular canals in a skeleton of irregularly oriented and spaced small hexactines. It is from late Viséan rocks of Sierra de la Estrella, near Espiel in Córdoba. The reticulosid Stereodictyum orthoplectum Finks, 1960 was collected from Viséan beds at Las Pilitas 2, Badajoz. It has a body wall of alternating layers of regularly spaced vertical and horizontal bundles of spicules in the quadrate-appearing skeleton. This is the first report of the genus from Europe and it is the oldest known occurrence of the genus. Upper Carboniferous sponges, Bashkirian to Moscovian-Kasimovian, have been collected from northern Spain. Demosponges include: Heliospongia excavate King, 1933; Coelocladia spinose Girty, 1908; small generically unidentifiable anthaspidellids; Haplistion Girty, 1908 sp. 1 and sp. 2; and a small fragmentary monaxonid demosponge of uncertain taxonomic assignment. Hexactinellida include the reticulosids, Stioderma perforate new species, and Stioderma Finks, 1960 sp. A, and the new amphidiscosids, Ascospongiella capdevilae new genus and species and Hadrophragmos soleniscus new genus and species. Root tufts A, B, and C are of uncertain taxonomic assignment. [ABSTRACT FROM AUTHOR]