Journal Description
Fossil Studies
Fossil Studies
- formerly Fossils - is an international, peer-reviewed, open access journal on all aspects of palaeontology published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- Rapid Publication: first decisions in 16 days; acceptance to publication in 5.8 days (median values for MDPI journals in the first half of 2024).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
- Fossil Studies is a companion journal of Diversity.
Latest Articles
A Craniometric Analysis of the Subfamily Cervinae (Cervidae, Mammalia)
Foss. Stud. 2024, 2(3), 196-222; https://doi.org/10.3390/fossils2030010 - 9 Sep 2024
Abstract
This study employs Principal Component Analysis to examine cranial measurements from both extant and fossil specimens spanning 38 species and comprising over 300 individuals within the subfamily Cervinae. Our findings elucidate craniometric distinctions among cervids characterized by varying body sizes and certain evolutionary
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This study employs Principal Component Analysis to examine cranial measurements from both extant and fossil specimens spanning 38 species and comprising over 300 individuals within the subfamily Cervinae. Our findings elucidate craniometric distinctions among cervids characterized by varying body sizes and certain evolutionary adaptations. While our results generally corroborate previous assertions regarding the limited craniometric variability among plesiometacarpal deer, they also unveil specific cranial adaptations within certain genera and species. The Principal Component Analysis of craniometric data revealed that giant and large-sized deer display significantly broader ecomorphological diversity in cranial shape compared to small-sized deer. Secondly, small-sized deer exhibit greater uniformity in their cranial shape, appearing densely clustered on the factorial map. Thus, we conclude that body size imposes ecological constraints, limiting the available niches due to eco-physiological factors. This study demonstrates that endemic insular deer do not evolve consistent craniometric features attributable to insular isolation, while the cranial proportions of medium-to-small-sized deer delineate a ubiquitous morphological archetype characteristic of numerous cervid taxa spanning diverse phylogenetic lineages and sharing comparable body sizes. This group of “Dama-like” deer, characterized by similar body size, metabolic rates, ecological needs, and cranial morphometry, is referred to here as the fundamental eco-physiological type, typical of warm regions within the Palearctic and Oriental biogeographic realms.
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(This article belongs to the Special Issue Advances in Palaeontology—Feature Papers to Celebrate the Inaugural Issue of Fossil Studies)
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Open AccessFeature PaperArticle
Caletodraco cottardi: A New Furileusaurian Abelisaurid (Dinosauria: Theropoda) from the Cenomanian Chalk of Normandy (North-Western France)
by
Eric Buffetaut, Haiyan Tong, Jérôme Girard, Bernard Hoyez and Javier Párraga
Foss. Stud. 2024, 2(3), 177-195; https://doi.org/10.3390/fossils2030009 - 19 Aug 2024
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An articulated group of skeletal elements comprising a sacrum, both ilia and a first caudal vertebra, plus an isolated tooth found in immediate proximity to the bones, from the lower Cenomanian Chalk at Saint-Jouin-Bruneval (Seine-Maritime, Normandy, France) is described and attributed to a
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An articulated group of skeletal elements comprising a sacrum, both ilia and a first caudal vertebra, plus an isolated tooth found in immediate proximity to the bones, from the lower Cenomanian Chalk at Saint-Jouin-Bruneval (Seine-Maritime, Normandy, France) is described and attributed to a new genus and species of abelisaurid theropod, Caletodraco cottardi, on the basis of several characters of the sacrum and pelvis. The peculiar shape of the transverse process of the first caudal vertebra shows that Caletodraco cottardi differs from majungasaurine abelisaurids previously described from Europe, such as Arcovenator escotae, and belongs to the Furileusauria, a group of derived abelisaurids hitherto recognized only from South America. The presence of a furileusaurian abelisaurid in the Cenomanian of Normandy suggests that the biogeographical history of the Abelisauridae in Europe was more complex than hitherto admitted. Several previously described European abelisaurids, such as the Albian Genusaurus sisteronis, may in fact belong to the Furileusauria.
Full article
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Open AccessFeature PaperReview
Contributions to the Palaeobiodiversity of Psocodea (‘Psocoptera’) from Lebanese Amber: A Review
by
Marina Hakim and Dany Azar
Foss. Stud. 2024, 2(3), 160-176; https://doi.org/10.3390/fossils2030008 - 24 Jul 2024
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Psocodea has been globally reported in different Mesozoic and Cenozoic amber deposits, one of which is Early Cretaceous Lebanese amber. The latter is one of the oldest ambers, with rich biological inclusions, bringing about the discovery of multiple new taxa of arthropods, some
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Psocodea has been globally reported in different Mesozoic and Cenozoic amber deposits, one of which is Early Cretaceous Lebanese amber. The latter is one of the oldest ambers, with rich biological inclusions, bringing about the discovery of multiple new taxa of arthropods, some representing the earliest known records of their lineages. A total of fourteen psocodean species (of which one is an unidentified immature species) have been described to date from this material, which we review and discuss in this paper. A key for the identification of psocodean species discovered in Lebanese amber is also provided.
Full article
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Open AccessArticle
Middle Devonian actinopterygians from Lithuania and Belarus
by
Darja Dankina, Jonas Šečkus and Dmitry P. Plax
Foss. Stud. 2024, 2(3), 141-159; https://doi.org/10.3390/fossils2030007 - 12 Jul 2024
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In the Baltic States and Belarus, the Middle Devonian period is characterised by an abundant fossil record of invertebrates such as scolecodonts, brachiopods, ostracods, trilobites, bivalves, crinoids, gastropods, and tentaculites. On the other hand, there was limited diversity in the conodont and other
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In the Baltic States and Belarus, the Middle Devonian period is characterised by an abundant fossil record of invertebrates such as scolecodonts, brachiopods, ostracods, trilobites, bivalves, crinoids, gastropods, and tentaculites. On the other hand, there was limited diversity in the conodont and other vertebrate fauna. In this study, we introduce a newly refined ichthyofaunal assemblage from the Eifelian and Givetian epochs from the present-day regions of Belarus and Lithuania. The isolated scales of Cheirolepis are identified as C. gaugeri, C. cf. gaugeri, C. aleshkai, C. cf. aleshkai, and Cheirolepis sp., while Orvikuina is represented by the isolated scales of O. vardiaensis and Orvikuina sp. The histological analyses for the scales of Orvikuina are provided here. Moreover, Orvikuina and Cheirolepis taxa are now recognised to be widely distributed throughout the Baltic States, especially Lithuania and Belarus, as a result of these findings. Thus, this ichthyofaunal data markedly improved the biostratigraphic correlation within the study region and expanded the paleogeographic distribution of these taxa during the Eifelian and Givetian time in Laurasia.
Full article
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Open AccessArticle
Enigmatic Discoid and Elliptical Structures from Brioverian (Ediacaran-Fortunian) Deposits of Brittany (Armorican Massif, NW of France)
by
Didier Néraudeau, Marc Poujol, Alfredo Loi and Jules Charrondière
Foss. Stud. 2024, 2(3), 123-140; https://doi.org/10.3390/fossils2030006 - 28 Jun 2024
Abstract
The Ediacaran–Cambrian deposits of Brittany (Brioverian series) contain both a few isolated pluricentimetric discoid structures, dome-shaped or “donut”-shaped, and a multitude of centimetric to infracentimetric more or less elliptical fossils or pseudofossils. The discoid and elliptical Brioverian structures are compared to similar fossils
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The Ediacaran–Cambrian deposits of Brittany (Brioverian series) contain both a few isolated pluricentimetric discoid structures, dome-shaped or “donut”-shaped, and a multitude of centimetric to infracentimetric more or less elliptical fossils or pseudofossils. The discoid and elliptical Brioverian structures are compared to similar fossils and pseudofossils found worldwide, and interpreted considering both sedimentary and biological hypotheses. This synthesis of more or less enigmatical fossils from the Ediacaran–Fortunian deposits of Brittany completes the previous descriptions of more well-known discoid and elliptical Brioverian structures such as Nimbia-like and Chuaria-like fossils. It provides a better understanding of the diversity of the Brioverian fossils and original sedimentary structures.
Full article
(This article belongs to the Special Issue Advances in Palaeontology—Feature Papers to Celebrate the Inaugural Issue of Fossil Studies)
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Open AccessReview
The Wasps (Hymenoptera) from Lower Cretaceous Lebanese and Spanish Ambers
by
Sergio Álvarez-Parra and Dany Azar
Foss. Stud. 2024, 2(2), 110-122; https://doi.org/10.3390/fossils2020005 - 5 Jun 2024
Cited by 1
Abstract
Hymenoptera is the fourth-most diverse insect order today, including wasps, bees, bumblebees, and ants. They show a wide panoply of modes of life, such as herbivory, predation, parasitoidism, pollination, and eusociality. This group also includes a great number of extinct species from both
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Hymenoptera is the fourth-most diverse insect order today, including wasps, bees, bumblebees, and ants. They show a wide panoply of modes of life, such as herbivory, predation, parasitoidism, pollination, and eusociality. This group also includes a great number of extinct species from both amber and compression outcrops. Hymenopterans probably originated in the Paleozoic, although their oldest record is from the Middle or Late Triassic, and their diversity expanded since the Cretaceous. Here, we present a review of the Hymenoptera in Lower Cretaceous ambers from Lebanon (Barremian) and Spain (Albian), which is pivotal for the study of hymenopteran evolution. Hymenoptera in Lebanese ambers are represented by 32 species in 22 genera within 15 families, while in Spanish ambers, they correspond to 49 species in 40 genera within 18 families. Most of these species belong to the ‘Parasitica’, and only a few species have been assigned to the Aculeata. The group ‘Symphyta’ is represented by one species in Spanish amber. The paleobiogeography and possible paleobiologies of the species in these ambers are reviewed. Furthermore, checklists for all Hymenoptera species in Lebanese and Spanish ambers are provided.
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(This article belongs to the Special Issue Advances in Palaeontology—Feature Papers to Celebrate the Inaugural Issue of Fossil Studies)
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Open AccessArticle
When Abnormality Becomes Perennial in a Reduced Population: The Case of Altudostephanus longicostis gen. et sp. nov. (Valanginian Ammonites, South-Eastern France)
by
Didier Bert, Stéphane Bersac, Bernard Beltran and Léon Canut
Foss. Stud. 2024, 2(2), 92-109; https://doi.org/10.3390/fossils2020004 - 25 May 2024
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The discovery of the new ammonite Altudostephanus longicostis gen. et sp. nov. around the lower/upper Valanginian boundary (Lower Cretaceous) with a true longitudinal ribs pattern oriented in the direction of coiling is reported here for the first time for the Cretaceous. This character
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The discovery of the new ammonite Altudostephanus longicostis gen. et sp. nov. around the lower/upper Valanginian boundary (Lower Cretaceous) with a true longitudinal ribs pattern oriented in the direction of coiling is reported here for the first time for the Cretaceous. This character rises questions as this type of ornamentation is mainly represented in the Paleozoic or old Mesozoic taxa. Its study shows that it is not a ‘shell accident’ and that it belongs to a particular lineage of Olcostephaninae, in a restricted geographical area and in a progenetic evolutionary context derived from Olcostephanus, which justifies the introduction of the new monophyletic genus Altudostephanus gen. nov. The discovery of a specimen of Passendorferia sp. (Oxfordian, Upper Jurassic) with the same pattern allows us to consider that this capacity could have a genetic cause. It seems that the fixation of this character, otherwise strongly recessive, in A. longicostis gen. et sp. nov. could take place thanks to a founder effect and the drastic numerical reduction in the population. The geological reference section PIG5 (Moriez area, South-Eastern France) is described, and the problem of the conservation of ‘pyritic’ s.l. ammonites is addressed with a proposed methodology allowing their long-term conservation.
Full article
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Open AccessArticle
The Life and Death of Jamoytius kerwoodi White; A Silurian Jawless Nektonic Herbivore?
by
Michael E. Brookfield
Foss. Stud. 2024, 2(2), 77-91; https://doi.org/10.3390/fossils2020003 - 9 Apr 2024
Cited by 1
Abstract
Jamoytius kerwoodi, is a primitive, eel-like jawless vertebrate found uniquely in an Early Silurian (Llandovery epoch; 444–433 Ma) horizon near Lesmahagow, Scotland. This species is a rare component of a low-diversity dominantly nektonic detritus-feeding and herbivorous fauna living over an anoxic bottom
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Jamoytius kerwoodi, is a primitive, eel-like jawless vertebrate found uniquely in an Early Silurian (Llandovery epoch; 444–433 Ma) horizon near Lesmahagow, Scotland. This species is a rare component of a low-diversity dominantly nektonic detritus-feeding and herbivorous fauna living over an anoxic bottom and is found at the transition from a marine-influenced, probably brackish-water, deep-water basin to a shallower-water, less saline and likely freshwater basin. In the absence of true teeth, Jamoytius was probably a detritivore or herbivore feeding on Dictyocaris. Jamoytius may have a common ancestor with living lampreys, especially as their ectoparasitic mode of life might have evolved from ancestral detritivores or herbivores.
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(This article belongs to the Topic Problems and Hypotheses in Palaeontology)
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Open AccessArticle
The Diet of Metriorhynchus (Thalattosuchia, Metriorhynchidae): Additional Discoveries and Paleoecological Implications
by
Stéphane Hua, Jeff Liston and Jérôme Tabouelle
Foss. Stud. 2024, 2(1), 66-76; https://doi.org/10.3390/fossils2010002 - 20 Feb 2024
Abstract
A new metriorhynchid specimen with stomach contents is described here. Assigned to Metriorhynchus cf. superciliosus., this specimen has a clear longirostrine form as indicated by its gracile and elongated mandibular rami. This is the second example of gastric contents described for Metriorhynchidae.
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A new metriorhynchid specimen with stomach contents is described here. Assigned to Metriorhynchus cf. superciliosus., this specimen has a clear longirostrine form as indicated by its gracile and elongated mandibular rami. This is the second example of gastric contents described for Metriorhynchidae. This specimen’s preservation allows the identification of the gill apparatus remains of Leedsichthys, the giant suspension-feeding osteichthyan from the Jurassic, including its gill rakers. The gastric contents also contain remains of invertebrates. This specimen indicates that Leedsichthys was not the direct prey of these crocodiles but more that its body was scavenged by them. Longirostrine metriorhynchids were piscivorous but also opportunistic and may have had more of a scavenging component in their lifestyle than previously understood, as all discovered fossils point in this direction.
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(This article belongs to the Special Issue Advances in Palaeontology—Feature Papers to Celebrate the Inaugural Issue of Fossil Studies)
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Open AccessFeature PaperArticle
Taxonomic Status of Nanotyrannus lancensis (Dinosauria: Tyrannosauroidea)—A Distinct Taxon of Small-Bodied Tyrannosaur
by
Nicholas R. Longrich and Evan T. Saitta
Foss. Stud. 2024, 2(1), 1-65; https://doi.org/10.3390/fossils2010001 - 3 Jan 2024
Cited by 5
Abstract
Tyrannosaurs are among the most intensively studied and best-known dinosaurs. Despite this, their relationships and systematics are highly controversial. An ongoing debate concerns the validity of Nanotyrannus lancensis, interpreted either as a distinct genus of small-bodied tyrannosaur or a juvenile of Tyrannosaurus
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Tyrannosaurs are among the most intensively studied and best-known dinosaurs. Despite this, their relationships and systematics are highly controversial. An ongoing debate concerns the validity of Nanotyrannus lancensis, interpreted either as a distinct genus of small-bodied tyrannosaur or a juvenile of Tyrannosaurus rex. We examine multiple lines of evidence and show that the evidence strongly supports recognition of Nanotyrannus as a distinct species for the following reasons: 1. High diversity of tyrannosaurs and predatory dinosaurs supports the idea that multiple tyrannosaurids inhabited the late Maastrichtian of Laramidia; 2. Nanotyrannus lacks characters supporting referral to Tyrannosaurus or Tyrannosaurinae but differs from T. rex in >150 morphological characters, while intermediate forms combining the features of Nanotyrannus and T. rex are unknown; 3. Histology shows specimens of Nanotyrannus showing (i) skeletal fusions, (ii) mature skull bone textures, (iii) slow growth rates relative to T. rex, (iv) decelerating growth in their final years of life, and (v) growth curves predicting adult masses of ~1500 kg or less, showing these animals are subadults and young adults, not juvenile Tyrannosaurus; 4. growth series of other tyrannosaurids, including Tarbosaurus and Gorgosaurus, do not show morphological changes proposed for a Nanotyrannus–Tyrannosaurus growth series, and deriving Tyrannosaurus from Nanotyrannus requires several changes inconsistent with known patterns of dinosaur development; 5. Juvenile T. rex exist, showing diagnostic features of Tyrannosaurus; 6. Phylogenetic analysis suggests that Nanotyrannus may lie outside Tyrannosauridae. Tyrannosaur diversity before the K-Pg extinction is higher than previously appreciated. The challenges inherent in diagnosing species based on fossils mean paleontologists may be systematically underestimating the diversity of ancient ecosystems.
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(This article belongs to the Special Issue Advances in Palaeontology—Feature Papers to Celebrate the Inaugural Issue of Fossil Studies)
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Open AccessEditorial
Minor Title Change: Fossils Becomes Fossil Studies
by
Eric Buffetaut and Fossil Studies Editorial Office
Foss. Stud. 2023, 1(1), 76; https://doi.org/10.3390/fossils1010008 - 20 Dec 2023
Abstract
The journal Fossils [...]
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Open AccessArticle
A Prognathodontin Mosasaur from the Maastrichtian of the Dakhla Oasis, Western Desert, Egypt
by
Gebely A. Abu El-Kheir, Ahmed A. Shaker, Hallie P. Street, Nicholas R. Longrich, Amin Strougo, Anhar Asan and Mohamed AbdelGawad
Foss. Stud. 2023, 1(1), 60-75; https://doi.org/10.3390/fossils1010007 - 9 Nov 2023
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Mosasaurs were diverse in the Upper Cretaceous in Africa, but relatively little is known about the mosasaur fauna of Egypt. Here, associated teeth and postcranial skeletal elements are reported for a mosasaur from the Maastrichtian Dakhla Shale of the Dakhla Oasis. The specimen
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Mosasaurs were diverse in the Upper Cretaceous in Africa, but relatively little is known about the mosasaur fauna of Egypt. Here, associated teeth and postcranial skeletal elements are reported for a mosasaur from the Maastrichtian Dakhla Shale of the Dakhla Oasis. The specimen includes tooth crowns, cervical, dorsal, and caudal vertebrae, and ribs. Teeth and bones exhibit features allowing referral to Prognathodontini. The teeth are relatively straight and blunt, suggesting affinities with Prognathodon overtoni or P. currii. Prognathodontins were important predators in the Maastrichtian of Africa, previously being recorded in Morocco, Congo, and Angola.
Full article
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Open AccessFeature PaperArticle
The First Dinosaur from the Kingdom of Cambodia: A Sauropod Fibula from the Lower Cretaceous of Koh Kong Province, South-Western Cambodia
by
Vanchan Lim, Eric Buffetaut, Haiyan Tong, Lionel Cavin, Kimchhay Pann and Phalline Polypheakdey Ngoeun
Foss. Stud. 2023, 1(1), 49-59; https://doi.org/10.3390/fossils1010006 - 2 Nov 2023
Abstract
The first discovery of a dinosaur bone from the Kingdom of Cambodia is reported in this paper. It consists of a sauropod fibula from a sandstone layer on Koh Paur island, in Koh Kong province, in south-western Cambodia. The dinosaur-bearing bed belongs to
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The first discovery of a dinosaur bone from the Kingdom of Cambodia is reported in this paper. It consists of a sauropod fibula from a sandstone layer on Koh Paur island, in Koh Kong province, in south-western Cambodia. The dinosaur-bearing bed belongs to the non-marine Grès Supérieurs series and is apparently of Early Cretaceous age. On the basis of various characters, notably the development of the anteromedial crest, the dinosaur fibula from Koh Paur is referred to a euhelopodid titanosauriform. This first dinosaur discovery in Cambodia suggests that the thick non-marine formations which cover vast areas in the south-western part of the country are potentially an important source of continental Mesozoic vertebrates.
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(This article belongs to the Special Issue Advances in Palaeontology—Feature Papers to Celebrate the Inaugural Issue of Fossil Studies)
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Open AccessBook Review
Book Review: Weedon, G.P.; Chapman, S.D. Ichthyosaurs from the Early Jurassic of Britain; Monograph Series; Siri Scientific Press: Manchester, UK, 2022; ISBN: 978-1-8381528-6-4
by
Eric Buffetaut
Foss. Stud. 2023, 1(1), 47-48; https://doi.org/10.3390/fossils1010005 - 22 Sep 2023
Abstract
The often beautifully preserved ichthyosaurs from the early Jurassic of Britain occupy a special place in the history of palaeontology [...]
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Open AccessArticle
The Hydrodynamics of Ammonoid Swimming: Equations of Motion and Rocking Resonances
by
Fabio Vittorio De Blasio
Foss. Stud. 2023, 1(1), 34-46; https://doi.org/10.3390/fossils1010004 - 19 Sep 2023
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This work explores the swimming of ammonoids, cephalopods related to living squids, octopuses, and nautilids and, like the latter, equipped with a coiled external shell. A mathematical model is introduced for theoretical ammonoid conchs. The two differential equations of motion (one for the
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This work explores the swimming of ammonoids, cephalopods related to living squids, octopuses, and nautilids and, like the latter, equipped with a coiled external shell. A mathematical model is introduced for theoretical ammonoid conchs. The two differential equations of motion (one for the centre of mass, including the drag force and the added mass coefficient, and one for the roll angle) are solved numerically for the theoretical conchs, and the results are analysed in terms of velocity and rocking angle. Destabilising resonances occur when the rocking motion is in phase with the propelling water jet. It is suggested that the ammonoids partly evolved avoiding the occurrence of such resonances in their construction.
Full article
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Open AccessArticle
First Fossil of Tylidae (Isopoda: Oniscidea) in Kachin Amber, Myanmar, with a List of All Oniscidea Fossil Records
by
Jinbo Lu, Stefano Taiti, Sheng Li, Yuanyuan Lu, De Zhuo, Xinpu Wang and Ming Bai
Foss. Stud. 2023, 1(1), 15-33; https://doi.org/10.3390/fossils1010003 - 17 May 2023
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A fossil of Oniscidea, Tylidae gen. et sp. indet. from Kachin amber (Cretaceous Cenomanian), Myanmar, is described here. The convex body, the cephalon with a triangular protrusion between the antennae, and pereonites 2–6 with epimera demarcated from tergites indicate that this specimen belongs
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A fossil of Oniscidea, Tylidae gen. et sp. indet. from Kachin amber (Cretaceous Cenomanian), Myanmar, is described here. The convex body, the cephalon with a triangular protrusion between the antennae, and pereonites 2–6 with epimera demarcated from tergites indicate that this specimen belongs to the family Tylidae, but since it is not an adult the identification of the genus and species is uncertain. This specimen has a convex body and shows an ability to conglobate, like all Tylidae. It is the first specimen of Oniscidea with a conglobation ability found in Burmese amber. Up to now, the fossil record of terrestrial isopods has included a total of 20 families and 54 records (36 species and 18 not formally identified species), 20% of which are from the Cretaceous period. These fossil records from the Cretaceous period show that terrestrial isopods were highly diversified as early as in the Cenomanian.
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Open AccessFeature PaperArticle
Stelladens mysteriosus: A Strange New Mosasaurid (Squamata) from the Maastrichtian (Late Cretaceous) of Morocco
by
Nicholas R. Longrich, Nour-Eddine Jalil, Xabier Pereda-Suberbiola and Nathalie Bardet
Foss. Stud. 2023, 1(1), 2-14; https://doi.org/10.3390/fossils1010002 - 17 May 2023
Cited by 4
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Mosasaurids, a clade of specialized marine squamates, saw a major adaptive radiation in the Late Cretaceous, evolving a wide range of body sizes, shapes, and specialized tooth morphologies. The most diverse known mosasaurid faunas come from the late Maastrichtian phosphates of Morocco. Here,
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Mosasaurids, a clade of specialized marine squamates, saw a major adaptive radiation in the Late Cretaceous, evolving a wide range of body sizes, shapes, and specialized tooth morphologies. The most diverse known mosasaurid faunas come from the late Maastrichtian phosphates of Morocco. Here, we report an unusual new mosasaurid, Stelladens mysteriosus, based on a partial jaw and associated tooth crowns from lower Couche III phosphatic deposits at Sidi Chennane, Oulad Abdoun Basin, Morocco. Stelladens is characterized by short, triangular tooth crowns with a series of strong, elaborate, and serrated ridges on the lingual surface of the tooth, functioning as accessory carinae. Morphology of the teeth and associated jaw fragment suggest affinities with Mosasaurinae. No close analogues to the unique tooth morphology of Stelladens are known, either extant or extinct. It may have had an unusual and highly specialized diet, a specialized prey-capture strategy, or both. The diversity of mosasaurid teeth is much higher than that of plesiosaurs, ichthyosaurs, or extant marine mammals, and likely reflects both the ecological diversity of mosasaurids and complex developmental mechanisms responsible for tooth formation in mosasaurines. Mosasaurid diversity continued to increase up to the Cretaceous–Paleogene boundary.
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Fossils—A New Open Access Journal
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Eric Buffetaut
Foss. Stud. 2023, 1(1), 1; https://doi.org/10.3390/fossils1010001 - 4 Apr 2023
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