[Paleontology • 2025] Palaeocampa anthrax • An armored freshwater Lobopodian (Panarthropoda: Aysheaiidae) with chemical defenses from the Carboniferous

 Palaeocampa anthrax Meek & Worthen, 1865
A large (40 mm) Palaeocampa anthrax is depicted at the edge of a shallow inland streambed, shadowed by the lush vegetation and mist of a coal forest, flanked by several euthycarcinoids, Sottyxerxes multiplex116 (max size ~35 mm), and a pair of freshwater xiphosurans, Alanops magnificus (max size ~25 mm). The nearest ocean environment is several hundred kilometers southwest.

in Knecht, McCall, Tsai, Childers et Yu. 2025.  

DOI: doi.org/10.1038/s42003-025-08483-0 

 

Abstract

Lobopodians are an evolutionary grade of panarthropods characterized by their vermiform bodies and paired, unjointed lobopodous legs. A paraphyletic group, their study is of particular significance in understanding the evolution of extant panarthropods. Found exclusively in marine deposits from the Paleozoic, the great majority of species come from Cambrian Konservat-Lagerstätten, with only a few representatives known from the Ordovician, Silurian, and Carboniferous. Here we redescribe Palaeocampa anthrax from the Carboniferous Mazon Creek (USA) and Montceau-les-Mines (France) Lagerstätten as a lobopodian. First published in 1865, nearly fifty years before the discovery of the Burgess Shale, Palaeocampa is historically the first discovered lobopod, and its presence at the slightly younger Montceau-les-Mines (Gzhelian), makes this the youngest known fossil ‘xenusiid’ lobopodian species. We present the case that Palaeocampa most likely inhabited a freshwater environment, contesting the view that Paleozoic lobopodians were exclusively marine. Palaeocampa bears biomineralized dorso-lateral and lateral sclerite sets with a unique architecture unseen in other lobopodian sclerites, which may have been capable of secreting defensive chemicals at their tips. Palaeocampa anthrax represents a major evolutionary step in lobopodians, both in environmental adaptations and in defensive abilities.

Systematic Paleontology 

Panarthropoda Nielsen, 1995

Family Aysheaiidae Walcott, 1911

†Palaeocampa Meek & Worthen, 1865

Type species: Palaeocampa anthrax Meek & Worthen, 1865, by monotypy.

Environmental reconstruction of the Montceau-les-Mines Lagerstätte with Palaeocampa anthrax.
A large (40 mm) Palaeocampa anthrax is depicted at the edge of a shallow inland streambed, shadowed by the lush vegetation and mist of a coal forest, flanked by several euthycarcinoids, Sottyxerxes multiplex116 (max size ~35 mm), and a pair of freshwater xiphosurans, Alanops magnificus (max size ~25 mm). The nearest ocean environment is several hundred kilometers southwest.

 

Richard J. Knecht, Christian R. A. McCall, Cheng-Chia Tsai, Richard A. Rabideau Childers and Nanfang Yu. 2025. Palaeocampa anthrax, An armored freshwater Lobopodian with chemical defenses from the Carboniferous. Communications Biology. 8, 1080. DOI: doi.org/10.1038/s42003-025-08483-0 [23 July 2025]

https://x.com/Prehistorica_CM/status/1947947434832716068

  

[Paleontology • 2025] Primicaris larvaformis • A tiny Cambrian stem-mandibulate reveals Independent Evolution of Limb Ttagmatization and Specialization in early Euarthropods

Primicaris larvaformis  Zhang, Han, Zhang, Liu & Shu, 2003

in Liu, Zeng, Zhao, Y. Zhu, Li, Yin et M. Zhu, 2025. 

DOI: doi.org/10.1038/s41598-025-03544-0 

Abstract

The mandibulate euarthropods are the most speciose animal group, but the evolutionary gaps in origin of mandibulate body plan remain unresolved. Marrellomorphs, a common Paleozoic euarthropod group, had a long evolutionary history from Cambrian to Devonian. With computed microtomography, here we report the fine-scale soft-bodied morphoanatomy of the oldest marrellomorph Primicaris larvaformis, a millimeters-sized euarthropod from the ~ 518-million-year-old Chengjiang biota, China. Primicaris possesses a body plan featuring morphologically similar post-antennular biramous appendages, but also mandibulate diagnostic features including multi-segmented exopodites, a well-developed and differentiated hypostome-labrum complex, and a pancrustacean-like topological configuration of frontalmost three pairs of appendages. Phylogenetic analysis resolves Acercostraca and Marrellida as stem-Mandibulata. The undifferentiated post-antennular appendages in Primicaris suggest a possibility that the head appendages acquired a crown-mandibulate configuration before their morphological specialization in mandibulate origin. The emergence of novel appendage morphotypes in Acercostraca and Marrellida reveals that the complexity of limb tagmatization evolved independently in different Euarthropoda clades.

Keywords: Computed tomography, Limb tagmatization, Euarthropod, Mandibulate, Chengjiang biota, Cambrian explosion

Overall morphology of Primicaris larvaformis.
 (a) NIGP 200783A, optical photo, ventral view. (b, c) Juvenile specimens. (b) NIGP 200792, optical photo, ventral view. (c) NIGP 200791A, optical photo, dorsal view. (d, e) NIGP 200812 (see also in Fig. 3). (d) Optical photo, dorsal view. (e) Tomographic maximum projection image, dorsal view. (f) NIGP 200798A, optical photo, ventral view. (g) NIGP 200809A, optical photo, dorsal view. (h) NIGP 200810, optical photo, dorsal view. (i) NIGP 200813A, optical photo, ventral view. (j, k) NIGP 200799. (j) Optical photo, dorsal view. (k) SEM-EDS map of carbon. (i, m) NIGP 200817. (l) Optical photo, dorsal view. (m) SEM-EDS map of iron.

 a1–14, post-antennular appendage 1–14; ab, anterior border; an, antennule; ax, axial region; ba, base of appendage; dv, gut diverticulae; eb, eye bulge; er, eye ridge; gt, gut; ls1–11, lateral spine of dorsal shield 1–11; pl, pleural region; ps, posterior spine of dorsal shield; rg, ridge of dorsal shield; st, setae. 

Scale bars represent: 0.5 mm (a–m).

Systematic palaeontology

Phylum Euarthropoda Lankaster, 1904.

Order Acercostraca Lehmann, 1955.

Genus Primicaris Zhang, Han, Zhang, Liu and Shu, 2003

Primicaris larvaformis Zhang, Han, Zhang, Liu and Shu, 2003

Emended diagnosis: Small euarthropod with a body length less than 6 mm. Undivided dorsal shield with up to twelve pairs of lateral marginal spines and a pair of posterior spines. One pair of uniramous antennules is followed by up to 14 homonomous pairs of biramous appendages (emended from ref. 13).

 

Yao Liu, Han Zeng, Fangchen Zhao, Yuyan Zhu, Yimeng Li, Zongjun Yin and Maoyan Zhu. 2025. A tiny Cambrian stem-mandibulate reveals Independent Evolution of Limb Ttagmatization and Specialization in early Euarthropods. Scientific Reports. 15: 19115. DOI: doi.org/10.1038/s41598-025-03544-0 [31 May 2025]

[PaleoIchthyology • 2024] Miaojiaaspis dichotomus • A New Genus of galeaspids (Eugaleaspiformes: Tujiaaspidae) from the early Silurian Chongqing Lagerstätte, China

 

Miaojiaaspis dichotomus 

Chen, Li, Zhou, Shan, Y.-A. Zhu, Wang, Wei & M. Zhu, 2024

 https://www.vertpala.ac.cn/EN/10.19615/j.cnki.2096-9899.240820 

 

The early Silurian Chongqing Lagerstätte (middle Telychian) yields exceptionally preserved articulated jawless and jawed fishes. Here, we describe a new eugaleaspiform (Galeaspida, jawless stem-Gnathostomata), Miaojiaaspis dichotomus gen. et sp. nov., from the Chongqing Lagerstätte in Xiushan, Chongqing, China. The new form resembles Tujiaaspis vividus in the short medial dorsal canal, and the presence of the branching ends of the lateral transverse canal. They differ in that T. vividus has highly developed subordinate branches of the sensory canals that form a reticulate sensory canal system, and the median dorsal opening is more elongated. Our phylogenetic analysis recovers M. dichotomus and T. vividus as a monophyletic clade (Tujiaaspidae fam. nov.), which is supported by two synapomorphies: the short medial dorsal canal, and the branching ends of the lateral transverse canal. Tujiaaspidae forms a trichotomy with Shuyuidae and a clade comprising Anjiaspis, Sinogaleaspidae, Yongdongaspidae, and the ‘eugaleaspid cluster’. The sensory canal patterns in galeaspids are compared to show the transformation sequence of the sensory canal system in Eugaleaspiformes.

Photographs (A, C) and interpretative drawings (B, D) of Miaojiaaspis dichotomus gen. et sp. nov. from Xiushan, Chongqing
A, B. an incomplete internal mold of the headshield with the trunk articulated, CIGMR V0125a; C, D. an incomplete external mold of the headshield with the trunk articulated, holotype, CIGMR V0125b

Subclass Galeaspida Tarlo, 1967

Order Eugaleaspiformes (Liu, 1965) Liu, 1980

Family Tujiaaspidae fam. nov.

Type genus Tujiaaspis Gai et al., 2022.

Referred genus Miaojiaaspis gen. nov.

Differential diagnosis Tujiaaspidae differs from other families of Eugaleaspiformes in the short medial dorsal canal, and the branching ends of the lateral transverse canal.

Remarks Our phylogenetic analysis shows that M. dichotomus and T. vividus form a monophyletic clade supported by two synapomorphies.

Genus Miaojiaaspis gen. nov.

Type species Miaojiaaspis dichotomus sp. nov.

Etymology From Miaojia, Pinyin for the Miao People, a minority ethnic group in China, which is one of the two main autonomous minority ethnic groups in Xiushan County, Chongqing, and aspis (Gr.), shield.

Differential diagnosis M. dichotomus differs from T. vividus in a more subtriangular headshield, no highly developed subordinate branches of sensory canals and a shorter median dorsal opening.

Miaojiaaspis dichotomus sp. nov.

Holotype An incomplete headshield with the trunk articulated, CIGMR V0125a, b (Figs. 2–3).

Referred specimens 8 complete headshields, CIGMR V0126–V0129, IVPP V28714–V28717 (Fig. 4).

Etymology From dichotomus (Latin), referring to the dichotomous ends of the lateral transverse canals.

Diagnosis Small-sized eugaleaspiform fish with a subtriangular headshield. Spine-shaped cornual and inner cornual processes caudo-laterally or caudally oriented. Longitudinal oval-like median dorsal opening. Pineal opening positioned behind the posterior margin of the orbits. Funnel-shaped supraorbital canals. Short medial dorsal canal. 

 

CHEN Yang, LI Qiang, ZHOU Zheng-Da, SHAN Xian-Ren, ZHU You-An, WANG Qian, WEI Guang-Biao, ZHU Min. 2024. A New Genus of galeaspids (jawless stem-Gnathostomata) from the early Silurian Chongqing Lagerstätte, China. Vertebrata Palasiatica. 62(4); 245-261.  DOI: 10.19615/j.cnki.2096-9899.240820 

 https://www.vertpala.ac.cn/EN/10.19615/j.cnki.2096-9899.240820 

[Paleontology • 2024] Douglassarachne acanthopoda • A remarkable Spiny Arachnid (Arachnida: Pantetrapulmonata) from the Pennsylvanian Mazon Creek Lagerstätte, Illinois

 Douglassarachne acanthopoda 

 Selden & Dunlop, 2024

 

DOI: 10.1017/jpa.2024.13 

 

Abstract

A new genus and species of arachnid (Chelicerata: Arachnida), Douglassarachne acanthopoda n. gen. n. sp., is described from the late Carboniferous (Moscovian) Coal Measures of the Mazon Creek Lagerstätte, Illinois, USA. This is a unique animal with distinctive large spines on the legs. It has a subovate body, a segmented opisthosoma, and a terminal anal tubercle. The legs are robust and appear to have been similar in construction throughout the limb series, with heavy spination of the preserved proximal podomeres. The mouthparts and coxo-sternal region are equivocal. The preserved character combination does not permit easy referral to any known arachnid order, living or extinct, thus the new fossil in placed as Arachnida/Pantetrapulmonata incertae sedis. It contributes to an emerging pattern of disparate body plans among late Carboniferous arachnids, ranging from anatomically modern members of living orders through to extinct taxa, such as the present fossil, whose phylogenetic position remains unresolved.

 Douglassarachne acanthopoda n. gen. n. sp., holotype and only known specimen FMNH PE 91366.
 (1) Photograph of part; (2) explanatory drawing of part; (3) photograph of counterpart; (4) explanatory drawing of counterpart; 1–4 = leg numbers; a t = anal tubercle; e t = eye tubercle; fe = femur; t = tergite. Scale bars = 5 mm.

 Douglassarachne acanthopoda n. gen. n. sp., reconstruction of the possible appearance of the animal in life.

Systematic paleontology

Class Arachnida Lamarck, Reference Lamarck, 1801

Pantetrapulmonata incertae sedis

Genus Douglassarachne new genus

Type species: Douglassarachne acanthopoda new species, by monotypy.

 

The genus is named for the Douglass family who kindly donated the specimen to the Field Museum for study.

 

Douglassarachne acanthopoda new species

Diagnosis: Relatively large arachnid (body length >15 mm) with median dorsal ocular tubercle on carapace, abdominal tergites, anal tubercle, legs bearing many long, curved macrospines.

Etymology: From the Greek αγκάθι, a thorn or prickle, and πόδι, leg, with reference to the very spiny legs of this animal.

Paul A. Selden and Jason A. Dunlop. 2024. A remarkable Spiny Arachnid from the Pennsylvanian Mazon Creek Lagerstätte, Illinois. Journal of Paleontology. DOI: doi.org/10.1017/jpa.2024.13 

Non-technical Summary: The forests of the late Carboniferous period (about 300–320 million years ago) harbored a great variety of arachnids. In addition to the familiar spiders, harvestmen, and scorpions, there were other, stranger kinds of spider-like animals. Here, we describe a large spider-like arachnid with very spiny legs (presumably to deter predators), from the world-famous Mazon Creek fossil localities of Illinois, USA.

[Paleontology • 2024] The Marine Conservation Deposits of Monte San Giorgio (Switzerland & Italy): the Prototype of Triassic Black Shale Lagerstätten

 

The marine conservation deposits of Monte San Giorgio (Switzerland, Italy): the prototype of Triassic black shale Lagerstätten.

in Klug, Spiekman, Bastiaans, Scheffold et Scheyer, 2024.

 DOI: 10.1186/s13358-024-00308-7 

Abstract

Marine conservation deposits (‘Konservat-Lagerstätten’) are characterized by their mode of fossil preservation, faunal composition and sedimentary facies. Here, we review these characteristics with respect to the famous conservation deposit of the Besano Formation (formerly Grenzbitumenzone; including the Anisian–Ladinian boundary), and the successively younger fossil-bearing units Cava inferiore, Cava superiore, Cassina beds and the Kalkschieferzone of Monte San Giorgio (Switzerland and Italy). We compare these units to a selection of important black shale-type Lagerstätten of the global Phanerozoic plus the Ediacaran in order to detect commonalities in their facies, genesis, and fossil content using principal component and hierarchical cluster analyses. Further, we put the Monte San Giorgio type Fossillagerstätten into the context of other comparable Triassic deposits worldwide based on their fossil content. The results of the principal component and cluster analyses allow a subdivision of the 45 analysed Lagerstätten into four groups, for which we suggest the use of the corresponding pioneering localities: Burgess type for the early Palaeozoic black shales, Monte San Giorgio type for the Triassic black shales, Holzmaden type for the pyrite-rich black shales and Solnhofen type for platy limestones.

Keywords: Konservat-Lagerstätten, Taphonomy, Marine reptiles, Exceptional preservation

Three important marine reptiles from the Middle Triassic of Monte San Giorgio with their reconstructions, recently crafted by Beat Scheffold. 

A Tanystropheus, PIMUZ T 2817. B Cyamodus, PIMUZ T58. C, Mixosaurus, PIMUZ T 4923 (top) and PIMUZ T 4376 (bottom)

Fossilized foetuses inside the mother, examples from the Middle Triassic of Monte San Giorgio. A Mixosaurus, PIMUZ T 4830 (e.g., Brinkmann, 1996; Miedema et al., 2023). B Saurichthys, PIMUZ T 3917 (e.g., Maxwell et al., 2018)

Fossilized mollusks from the Middle Triassic of Monte San Giorgio (see Rieber, 1969, 1970, 1973; Pieroni, 2022). 

A, Proarcestes extralabiatus, internal mould. B, Repossia acutenodosa, silicified internal mould. C, Proarcestes extralabiatus, external mould. D, Phragmoteuthis ticinensis with complete arm crown, cephalic cartilage, oesophagus and ink sac. E, Daonella caudata. F, Pleuronautilus sp., internal mould

Some animals from Monte San Giorgio.
 Note that not all of the depicted taxa may have co-occurred in time or in space (habitat depth, etc.). At Monte San Giorgio, the water depth was likely greater then shown in these images.
A Meride Limestone (Ladinian). B Besano Formation (Anisian)

Reconstructions by Beat Scheffold.  

Conclusions: 

The conservation deposits of Anisian and Ladinian age of Monte San Giorgio, comprising the Besano Formation, Cava inferiore, Cava superiore, Cassina Beds, and the Kalkschieferzone, represent some of the first black shale conservation deposits of Triassic age that were thoroughly studied. Now, after a century of excavations and more than a century of research, these deposits begin to enjoy global scientific recognition (e.g., Etter, 2002a; Rieppel, 2019), and continue to produce valuable new information about the palaeobiology and evolution of Triassic vertebrates today.

With this paper, we want to highlight the key role of the conservation deposits of Monte San Giorgio: comparable to the pioneer role of the Burgess Shale for the Cambrian Lagerstätten or Solnhofen for the Mesozoic platy limestones, we highlight the pioneer role of the Besano Formation in particular as the prototype for Triassic Lagerstätten. Our simple comparison of 45 Fossillagerstätten worldwide employing principal component and hierarchical cluster analyses of 32 traits based on the ...

Christian Klug, Stephan N. F. Spiekman, Dylan Bastiaans, Beat Scheffold and Torsten M. Scheyer. 2024. The Marine Conservation Deposits of Monte San Giorgio (Switzerland, Italy): the Prototype of Triassic Black Shale Lagerstätten.  Swiss Journal of Palaeontology. 143, 11. DOI: doi.org/10.1186/s13358-024-00308-7 

 

[Paleontology • 2024] Omnidens qiongqii • Omnidens Appendages and the Origin of Radiodont Mouthparts

 

Omnidens qiongqii 

Li, J. Yang, X. Yang, Dhungana, Wang, Zhang & Smith, 2024

 

DOI: 10.1002/spp2.1600 

Abstract

The sophisticated, modular and adaptable body plan of arthropods underpins their dominance in marine invertebrate communities. The origin of this body plan from legged lobopodian worms can be inferred from Cambrian Konservat-Lagerstätten, but our understanding retains some notable gaps: not least in the transition from swimming lobopodians such as Kerygmachela and Pambdelurion to robustly sclerotized radiodonts such as Anomalocaris. A large Pambdelurion-like fossil from the Xiaoshiba biota, Omnidens qiongqii sp. nov., exhibits a novel combination of characters: an oral apparatus with a non-radial configuration; and centimetric talon-like grasping structures with heavily sclerotized blade-like spines. The novel morphology broadens the interpretative framework for associated Cambrian taxa, demonstrating continuity in the morphology of euarthropod appendages prior to the origin of podomeres. A reappraisal of the euarthropod stem lineage suggests that radially arranged mouthparts may be a radiodont novelty, rather than an inheritance from the ancestral ecdysozoan. These results further resolve the evolutionary origins of the euarthropod body plan.

Keywords: Omnidens, evolutionary novelty, Cambrian explosion, Burgess Shale-type Lagerstätten, Panarthropoda

 Omnidens qiongqii sp. nov.

 

Wei Li, Jie Yang, Xiaoyu Yang, Alavya Dhungana, Yu Wang, Xiguang Zhang and Martin R. Smith. 2024. Omnidens Appendages and the Origin of Radiodont Mouthparts. Papers in Palaeontology. DOI: doi.org/10.1002/spp2.1600 

  x.com/ThePalAss/status/1851901038845997459

[PaleoIchthyology • 2023] Dasyomyliobatis thomyorkei (Chondrichthyes: Myliobatiformes) • The Evolutionary Origin of the durophagous Pelagic Stingray Ecomorph

Dasyomyliobatis thomyorkei  

 Marramà, Villalobos-Segura, Zorzin, Kriwet & Carnevale, 2023

 DOI: 10.1111/pala.12669

 Artworks by Fabrizio Lavezzi.

 

Abstract

Studies of the origin of evolutionary novelties (novel traits, feeding modes, behaviours, ecological niches, etc.) have considered a number of taxa experimenting with new body plans, allowing them to occupy new habitats and exploit new trophic resources. In the marine realm, colonization of pelagic environments by marine fishes occurred recurrently through time. Stingrays (Myliobatiformes) are a diverse clade of batoid fishes commonly known to possess venomous tail stings. Current hypotheses suggest that stingrays experimented with a transition from a benthic to a pelagic/benthopelagic habitat coupled with a transition from a non-durophagous diet to extreme durophagy. However, there is no study detailing macroevolutionary patterns to understand how and when habitat shift and feeding specialization arose along their evolutionary history. A new exquisitely preserved fossil stingray from the Eocene Konservat-Lagerstätte of Bolca (Italy) exhibits a unique mosaic of plesiomorphic features of the rajobenthic ecomorph, and derived traits of aquilopelagic taxa, that helps to clarify the evolutionary origin of durophagy and pelagic lifestyle in stingrays. A scenario of early evolution of the aquilopelagic ecomorph is proposed based on new data, and the possible adaptive meaning of the observed evolutionary changes is discussed. The body plan of †Dasyomyliobatis thomyorkei gen. et sp. nov. is intermediate between the rajobenthic and more derived aquilopelagic stingrays, supporting its stem phylogenetic position and the hypothesis that the aquilopelagic body plan arose in association with the evolution of durophagy and pelagic lifestyle from a benthic, soft-prey feeder ancestor.

Keywords: durophagy, ecomorph, evolution, Myliobatiformes, pelagic lifestyle, stingray

†Dasyomyliobatis thomyorkei gen. et sp. nov. from the Eocene of Monte Bolca (Italy).
 MCSNV VR.21.107, holotype, dorsoventral view natural normal light.

†Dasyomyliobatis thomyorkei gen. et sp. nov.  (MCSNV VR.21.107, holotype) showing its peculiar combination of rajobenthic (A–D) and aquilopelagic (E–H) traits:
A, small holaulacorhizous lateral teeth arranged in alternating rows; B, pectoral-fin radials with catenated calcification and no cross-bracing; C, free tail vertebrae without cartilaginous rod and caudal fin reduced to a ventral fold; D, soft, flexible pectoral disc with convex anterior and posterior margins; E, head protruding from pectoral disc; F, cephalic lobes; G, wing-like pectoral disc with positive FRD; H, enlarged hexagonal symphyseal/parasymphyseal polyaulacorhizous teeth in pavement-like arrangement. Scale bar represents 100 mm.

SYSTEMATIC PALAEONTOLOGY

Class CHONDRICHTHYES Huxley, 1880

Superorder BATOIDEA Compagno, 1973

Order MYLIOBATIFORMES Compagno, 1973

Family †DASYOMYLIOBATIDAE nov.

 

Genus †DASYOMYLIOBATIS nov.

 

Type species: †Dasyomyliobatis thomyorkei sp. nov.

Derivation of names: Genus and family names refer to the peculiar mosaic of dasyatoid and myliobatoid traits.

 

†Dasyomyliobatis thomyorkei sp. nov.

 

Derivation of name: After the British composer and musician Thom Yorke.

Holotype: MCSNV VR.21.107/8 well preserved, complete, and articulated skeleton in part and counterpart, 99.9 cm disc width.

Type locality & horizon: Pesciara site, Bolca Konservat-Lagerstätte, Italy; early Eocene, late Ypresian, middle Cuisian, SBZ-11, †Alveolina dainelli Zone, c. 50 Ma (Papazzoni et al. 2014).

Diagnosis: Stingray unique in having a peculiar combination of dasyatoid and myliobatoid traits. Like dasyatoids, †Dasyomyliobatis has a soft and flexible pectoral disc with convex anterior and posterior fin margins supported by catenated radials with no cross-bracing; numerous (c. 40) labiolingually directed files of holaulacorhizous lateral teeth arranged in alternating rows; tail formed by free vertebrae not stiffened by a cartilaginous rod; caudal fin reduced to a ventral fold. Like myliobatoids, †Dasyomyliobatis shows a head protruding anterior to a wing-like pectoral disc; cephalic lobes contacting along their mesial edge forming a single, shovel-like structure; cephalic-lobe radials discontinuous with pectoral-fin radials; moderately enlarged hexagonal symphyseal/parasymphyseal polyaulacorhizous teeth in pavement-like arrangement, with bulbous/irregular interlocking mechanism, 3–4 wide-block and irregularly spaced root lobes. In addition, †Dasyomyliobatis has a pectoral-fin AR between 2.0 and 3.0, and positive FRD.

Hypothetical reconstruction of †Dasyomyliobatis thomyorkei gen. et sp. nov. in different views.

Artwork by Fabrizio Lavezzi.

Life reconstruction of †Dasyomyliobatis thomyorkei gen. et sp. nov. swimming in the marine tropical shallow waters of the western Tethys about 50 million years ago.

 Artwork by Fabrizio Lavezzi.

CONCLUSIONS: 

The unique body plan of †Dasyomyliobatis suggests that:

• †Dasyomyliobatis is a representative of a new stingray family with unique hybrid dentition and pectoral-fin morphology that allowed the shift from undulatory to oscillatory swimming, and to exploit a variety of prey (from soft-bodied to hard-shelled organisms).

• The evolutionary origin of durophagy and pelagic lifestyle was achieved through gradual transformation of morphological traits at least since the early Late Cretaceous.

• Cephalic lobes were already present in a stingray without crustal calcification, cross-bracing, or compagibus laminam corroborating the hypothesis that they originated before the shift toward exclusive oscillatory locomotion and occupation of pelagic environments.

• The phylogenetic analyses highlight that evolutionary modifications of the dentition related to a shift toward extreme durophagy seem to covariate with the evolution of traits of pectoral skeleton related to a shift toward a pelagic lifestyle, possibly reflecting high level of integration. One can speculate that although invasion of new habitats allowed initially stingrays to exploit wider ranges of food items, competition with other benthic batoids like skates, known to occupy today the same niche as benthic stingrays in deeper and cooler waters (Ebert & Compagno 2007) but also warm and shallow waters during the Late Cretaceous (Cappetta 1980), pushed pelagic/benthopelagic stingrays to specialize for a less exploited food resource, like hard-shelled invertebrates, although this hypothesis needs to be tested.

Giuseppe Marramà, Eduardo Villalobos-Segura, Roberto Zorzin, Jürgen Kriwet and Giorgio Carnevale. 2023. The Evolutionary Origin of the durophagous Pelagic Stingray Ecomorph. Palaeontology. DOI: 10.1111/pala.12669

[PaleoIchthyology • 2023] Yanliaomyzon ingensdentes & Y. occisor • The Rise of Predation in Jurassic Lampreys

Yanliaomyzon occisor & Y. ingensdentes 

 Wu, Janvier & Zhang, 2023

DOI: 10.1038/s41467-023-42251-0

Abstract

Lampreys, one of two living lineages of jawless vertebrates, are always intriguing for their feeding behavior via the toothed suctorial disc and life cycle comprising the ammocoete, metamorphic, and adult stages. However, they left a meager fossil record, and their evolutionary history remains elusive. Here we report two superbly preserved large lampreys from the Middle-Late Jurassic Yanliao Biota of North China and update the interpretations of the evolution of the feeding apparatus, the life cycle, and the historic biogeography of the group. These fossil lampreys’ extensively toothed feeding apparatus differs radically from that of their Paleozoic kin but surprisingly resembles the Southern Hemisphere pouched lamprey, which foreshadows an ancestral flesh-eating habit for modern lampreys. Based on the revised petromyzontiform timetree, we argued that modern lampreys’ three-staged life cycle might not be established until the Jurassic when they evolved enhanced feeding structures, increased body size and encountered more penetrable host groups. Our study also places modern lampreys’ origin in the Southern Hemisphere of the Late Cretaceous, followed by an early Cenozoic anti-tropical disjunction in distribution, hence challenging the conventional wisdom of their biogeographical pattern arising from a post-Cretaceous origin in the Northern Hemisphere or the Pangean fragmentation in the Early Mesozoic.

Jurassic lampreys from the Yanliao Biota, China, Yanliaomyzon occisor gen. et sp. nov. and Yanliaomyzon ingensdentes gen. et sp. nov.
a–e Yanliaomyzon occisor gen. et sp. nov., a Photograph of holotype (IVPP V 15830); b Line drawing of the oral disc and dentition of (a), based on Supplementary Fig. 2k and l; c, d Paratype (IVPP V 18956B), photograph (c) and line drawing (d); e Restoration.
 f–h Yanliaomyzon ingensdentes gen. et sp. nov., f Photograph of holotype (IVPP V 16715B), white arrow pointing to the skeletal relics in gut content; g Oral disc and dentition; h Restoration.

Abbreviations: adf, ‘anterior dorsal fin’ (dorsal fin); af, anal fin fold; ba, branchial apparatus; ca, cloaca (anus); cot, circumoral teeth; da, dorsal aorta; dcf, dorsal lobe of caudal fin; dt, oral disc teeth; cf, caudal fin; e, eyes; dt, disc teeth; go, external gill openings; gp, gular pouch; ic, intestine contents; io, infraoral lamina; ll, longitudinal lingual lamina; ll.l, left longitudinal lingual lamina; ll.r, right longitudinal lingual lamina; lv, liver; ns, olfactory organ (nasal sac); oc, otic capsule; od, oral disc; of, oral fimbriae; op, oral papilla(e); paf, precloacal skin fold; pdf, ‘posterior dorsal fin’ (anterior part of caudal fin); pt, piston cartilage; so, supraoral lamina; tl, transverse lingual lamina; vcf, ventral lobe of caudal fin; V1?, ophthalmic ramus of trigeminal nerve?

a–d Oral disc and dentition of Yanliaomyzon ingensdentes gen. et sp. nov., a Photograph (IVPP V 16716B) and b Line drawing; c Photograph (IVPP V 16716A), whitened with ammonium chloride, the white arrow pointing to the imprints of the wrinkles of the gular pouch; d Restoration.
e, f Oral disc and dentition of Yanliaomyzon occisor gen. et sp. nov., e Photograph (IVPP V18956A), whitened with ammonium chloride; f Restoration;
 g Oral disc and dentition of Geotria australis, redrawn from ref. 10.
Abbreviations: cot, circumoral teeth; dt, oral disc teeth; gp, gular pouch; ic, intestine contents; io, infraoral lamina; ll, longitudinal lingual lamina; ll.r, right longitudinal lingual lamina; od, oral disc; of, oral fimbriae; op, oral papilla(e); so, supraoral lamina; tl, transverse lingual lamina.

Systematic paleontology

Order: Petromyzontiformes Berg, 194018

Genus Yanliaomyzon gen. nov.

 

Diagnosis: Stem lampreys with oral discs well-toothed in anterior and lateral fields; anterior and lateral oral disc teeth closely arranged, dorsally truncated, spatulate in shape with the slightly concaved undersurface of the free edge protruding a shallow blade; posterior disc teeth lacking, anterior and lateral circumoral teeth elongate and trihedral in shape; supraoral lamina large and consisting of two stout central cusps flanked by wing-like lateral extensions; transverse lingual lamina very large with the apices of three cusps interlocking with the supraoral lamina in vivo.

 

Etymology: ‘Yanliao’ derives from Yanliao Biota, a Jurassic terrestrial Lagerstätte from North China, where these fossils were discovered; ‘myzon’ (Greek), sucker.

Yanliaomyzon occisor

Diagnosis: The supraoral lamina spanning completely the lateral rims of the oral aperture, with the central cusps flanked immediately by two smaller projections; 16 circumoral teeth; the tail region occupying slightly less than 28% of the total body length.

Etymology: Latin ‘occisor’, meaning ‘killer’, refers to the powerful hunting skill of the species.

Horizon and locality: Tiaojishan Formation, Oxfordian, earliest Late Jurassic, ca. 158.58–160 million years ago (Ma); Daxishan, Linglongta Town, Jianchang County, Liaoning Province (Holotype), and Nanshimen Village, Gangou Town, Qinglong County, Hebei Province (Paratype), China.

Yanliaomyzon ingensdentes gen. et sp. nov.

Diagnosis: The supraoral lamina occupying roughly one-third of the rim of the oral aperture; the transverse lingual lamina almost equaling to the supraoral lamina in width; ca. 23 circumoral teeth; the tail region occupying slightly more than 40% of the total body length.

Etymology: Latin ‘ingens + dentes’, meaning large teeth, refers to the large cuspid laminae on the gouging piston.

 

Horizon and locality: Daohugou beds, Callovian, late Middle Jurassic, ca. 163 Ma in Wubaiding Village, Reshuitang County, Liaoning Province, China.

   

 

Feixiang Wu, Philippe Janvier and Chi Zhang. 2023. The Rise of Predation in Jurassic Lampreys. Nature Communications. 14: 6652. DOI: 10.1038/s41467-023-42251-0

https://phys.org/news/2023-11-species-large-ancient-lampreys-china.html

[Paleontology • 2023] Crococopros naduongensis • Exceptionally Well-preserved Crocodilian Coprolites from the Late Eocene of Northern Vietnam: Ichnology and Paleoecological Significance

The Eocene of Na Duong Basin is considered as a fossil Lagerstätte of Southeast Asia
Flora and fauna constituent in the drawing were an actual reconstruction based on palynology analyses, and of body fossil findings from various workers 

Crococopros naduongensis Halaçlar, Rummy, Liu, Hunt, Do, Minh & Deng, 2023

 DOI: 10.1016/j.isci.2023.107607

Illustration by Chung-Tat Cheung  facebook.com/ChungTatCheung

Highlights: 

• New ichnogenus and ichnospecies Crococopros naduongensis

• First quantitative study on crocodilian coprolites

• Multidisciplinary approach to understand paleoecology of Na Duong Basin

• Tangible evidence supporting Na Duong Basin as a fossil-Lagerstätte of Southeast Asia

Summary

This study examines 55 coprolites from the Na Duong Basin to reconstruct the paleoenvironment. Coproecology sheds light on understanding the complex prey-predator relationships, trophic dynamics, and ecosystem evolution. Through quantitative and multidisciplinary analysis, the putative coprolites were attributed to crocodilian producers, leading to the establishment of a new ichnogenus and species, Crococopros naduongensis igen. et isp. nov., based on distinct characteristics and comparisons. The study provides compelling evidence of an ancient river or lake-like environment dominated by diverse crocodilian fauna, indicating a thriving food chain in the Na Duong Basin. The findings also highlight the remarkable richness of ichnofauna, fauna, flora, and the presence of a favorable climate, confirming the area as a significant fossil Lagerstätte in Southeast Asia. Overall, this study offers a unique snapshot of the past, providing valuable insights into the regional ecosystem and significantly contributing to our understanding of paleoenvironmental conditions and biotic interactions.

Paleoenvironment reconstruction drawing reflects a real ‘snapshot’ of an intermittently swamped lacustrine–fluvial plain ecosystem with an abundance of crocodilians and testudines
 The Eocene of Na Duong Basin is considered as a fossil Lagerstätte of Southeast Asia (Flora and fauna constituent in the drawing were an actual reconstruction based on palynology analyses, and of body fossil findings from various workers).

Illustration by Chung-Tat Cheung

 

Kazım Halaçlar, Paul Rummy, Jia Liu, Adrian P. Hunt, Truong Van Do, Nguyen Trung Minh and Tao Deng. 2023. Exceptionally Well-preserved Crocodilian Coprolites from the Late Eocene of Northern Vietnam: Ichnology and Paleoecological Significance. iScience.   26(9); 107607. DOI: 10.1016/j.isci.2023.107607

 facebook.com/ChungTatCheung/posts/6637598082945031

 

[Paleontology • 2023] Vampyrofugiens atramentum • A New vampyromorph Species (Cephalopoda: Octobrachia) from the Middle Jurassic La Voulte-sur-Rhône Lagerstätte

Vampyrofugiens atramentum  

Rowe, Kruta, Villier & Rouget. 2023

DOI: 10.1002/spp2.1511

 (Artwork by A. Lethiers, CR2P)

Abstract

Eight coleoid genera have so far been described from the Callovian-aged La Voulte-sur-Rhône Lagerstätte (c. 165 Ma; Ardèche, France), a locality noted for its unique three-dimensional preservation of soft tissues. Here, we used high resolution x-ray-based imaging methods, in conjunction with reflectance transformation imaging, to study the soft tissues of a previously undescribed coleoid from the La Voulte-sur-Rhône locality. This analysis identified both an ink sac and internal light organs, a combination of defence mechanisms present in the Recent, although not previously described from the coleoid fossil record, as well as the presence of Octobrachia-type arm musculature and Vampyroteuthis-like sucker attachments. The morphology of the gladius could not be attributed to any known coleoids and therefore justified the assignment of this single specimen to a new taxon: Vampyrofugiens atramentum. The addition of this new vampyromorph species not only increases the coleoid diversity known from the site, but also broadens the morphological variation observed in the co-occurring coleoid taxa. These findings suggest that there was a high diversity of cephalopods occupying differentiated communities during the Middle Jurassic.

Keywords: soft-tissue preservation, Vampyromorpha, synchrotron microtomography, reflectance transformation imaging, coleoid, La Voulte-sur-Rhône Lagerstätte

Vampyrofugiens atramentum gen. et sp. nov. 
Photograph, 3D rendering, and PPC-SR-μCT slices (binned dataset, voxel size: 25.28 μm) of the undescribed specimen (MNHN.F.A32491) acquired at the ESRF (Grenoble, France).
A, photograph (P. Loubry, CR2P) of the specimen showing the 3D preservation of the mineralized soft tissue. B, composite of PPC-SR-μCT slices showing the greyscale contrast used to segment the specimen. C, 3D rendering showing the location of the fins (beige), ink sac (teal) and internal luminous organs (pink). D, longitudinal slice showing the location of the funnel, and an area interpreted to be remnants of the gladius in longitudinal view. Rendered in Mimics software (v.21.0).

 Scale bars represent: 10 mm (A–B); 2 mm (D).

SYSTEMATIC PALAEONTOLOGY

Superorder OCTOBRACHIA Haeckel, 1866

Order VAMPYROMORPHA Robson, 1929

Suborder LOLIGOSEPIINA Jeletzky, 1965

Family GEOPELTIDAE Regteren Altena, 1949

Genus VAMPYROFUGIENS nov.

Derivation of name: The name Vampyrofugiens is composed of the original Serbian word Vampir and the Latin fugiens (fleeing) to reflect the escape behaviours of this new vampyromorph taxon.

Vampyrofugiens atramentum sp. nov.

 

Derivation of the name: The species name atramentum (Latin word for ink) is assigned and reflects the occurrence of an ink sac.

Diagnosis: Mantle bullet-shaped; arm length moderate (arm length : mantle length ratio of 0.6 although the distal tips are not preserved), no elongated arm pair; suckers radially symmetrical, uniserial, sucker rings absent; cirri biserial; head dorsally fused with mantle; ink sac present; luminous organs present internally; fins subterminal.

Type locality: La Voulte-sur-Rhône, France.

Type horizon: Middle Jurassic (Lower Callovian), gracilis Biozone.

Hypothesized reconstruction of Vampyrofugiens atramentum gen. et sp. nov. based on the data from this study

 (Artwork by A. Lethiers, CR2P)

CONCLUSION: 

The use of high-resolution imaging techniques, PPC-SR-μCT and RTI, provides new observational data on the soft tissues, internal organs and gladius of an unpublished vampyromorph specimen (MNHN.F.A32491) from La Voulte-sur-Rhône.

The imaging shows that the individual had an Octobrachia-type arm configuration and musculature, Vampyroteuthis-like sucker attachments, an ink sac, and two internal light organs with anterior–posterior symmetry. The combination of the ink sac and internal luminous organs is known from the Recent, although not from fossil coleoids. Additionally, the observed gladius morphology in MNHN.F.A32491 differs from previously described coleoids and therefore justifies the assignment of this individual to a new taxon, Vampyrofugiens atramentum gen. et sp. nov.

Alison J. Rowe, Isabelle Kruta, Loïc Villier and Isabelle Rouget. 2023. A New vampyromorph Species from the Middle Jurassic La Voulte-sur-Rhône Lagerstätte. Papers in Palaeontology. 9(3); e1511. DOI: 10.1002/spp2.1511