Log In 
Language Spanish journal of palaeontology. 2022. Vol. 37, no. 2
Permanent URI for this collection
Browse
Recent Submissions
- Espiriféridos del Givetiense–Frasniense de la costa asturiana (España)(2022) García-Alcalde, Jenaro L.Se describen algunos braquiópodos espiriféridos del Givetiense superior al Frasniense inferior, de la costa asturiana (Norte de España), con los nuevos taxones Tenticospirifer? sinuosus n. sp., Eodmitria briceae n. sp., Apousiella mozarti n. sp., Apousiella dorlodoti peranensis n. subsp. y Apousiella belliloci aramaris n. subsp. La muestra representa la renovación faunística global relacionada con el Evento Tagánico. Ella permite precisar la correlación estratigráfica de las formaciones Candás y Piñeres del área y ayuda a reconocer una nueva estructura plegada: el anticlinal de Boletos. Ambos hechos, conducen a reafirmar la semejanza esencial de las sucesiones comparadas, y a rechazar la existencia de una gran fosa sedimentaria (“Surco de Luanco”) en el área de Antromero. La Formación Piñeres comprende, al menos, dos miembros: el inferior P1 muy fosilífero y el superior, P2 (Formación Piñeres sensu stricto), con restos orgánicos inidentificables. P1 es comparable con buena parte de la Formación Nocedo, del Frasniense, mientras que P2 equivale totalmente o en parte a la Formación Ermita, transgresiva, del Fameniense superior, en la provincia de León. Se propone una biozonación informal basada en los braquiópodos descritos aquí y en otros previamente conocidos, con las zonas plicatulus, verneuiliformis, peranensis, briceae, aramaris, y dumontiana. Las asociaciones asturianas muestran estrechas relaciones con las asociaciones fosilíferas francesas de Ferques (Bas Boulonnais, Francia), en particular con las de las formaciones Blacourt y Beaulieu.
- Pentaradiate diploporites (Echinodermata) from the Spanish Middle Ordovician and their taxonomic significance(2022) Paul, Christopher R.C.; Gutiérrez-Marcos, Juan CarlosNew Middle Ordovician specimens of pentaradiate diploporite blastozoans from the southern Central Iberian Zone, Spain, show that Oretanocalix is an aristocystitid diploporite with five ambulacra; all other aristocystitid genera have 2?4 ambulacra. The laterally elongate oral frame is composed of eight plates, with five, facet-bearing, circumorals (COO) and three, non-facet-bearing, periorals (POO). This necessitates a new interpretation of the aristocystitid oral area and diagnosis of the family Aristocystitidae. Previous interpretations assumed four COO and four POO. Weathered examples lack oral cover plates and show that plates CO1 and CO4, which support ambulacra D and B, respectively, do not reach the inner margin of the peristome. They also reveal abundant diplopores, which were covered by a thin epistereom in life. Diplopores grew at plate sutures and were incorporated into both adjacent plates as the plates enlarged. Oretanocalix julioi n. sp. extends the stratigraphic range of Oretanocalix back to the basal Dobrotivian ?low in the Upper Darriwilian. The genus Batalleria is a sphaeronitid diploporite with food grooves that branched within the peristome. The branching pattern reflects Lovén’s law and is: AR, BL, CR, DL, ER, where A?E denote Carpenter’s ambulacra and L (left) and R (right) denote on which side of the ambulacrum the first branch lies. Each branch leaves the peristome by a separate ambulacral orifice. No other sphaeronitids have food grooves that branch within the peristome and all other sphaeronitids have one ambulacral orifice per ambulacrum. Thus, a new diagnosis of sphaeronitids is necessary.
- The phylogenetic trees of Florentino Ameghino and cladograms: a case for multiple discovery?(2022) Casinos, AdriàThe topology of the phylogenetic trees used by Florentino Ameghino in his works Filogenia and Contribución al conocimiento de los mamíferos fósiles de la República Argentina, is analysed. The similarities with the topology of the present day cladograms, branching orthogonal diagrams with dichotomies, are highlighted and discussed.
- The confirmed fossil record of the blue shark Prionace glauca (Linnaeus, 1758) from the South Eastern Pacific(2022) Villafaña, Jaime A.; Kindlimann, René; Chavez-Hoffmeister, MartinWe offer the first formal description of fossil specimens of the blue shark Prionace glauca from Chile. The teeth described in this study were collected from the Mina Fosforita locality and preliminary assigned to the late Miocene. The confirmation of the presence of the blue shark in the Neogene sediments of Chile is a significant contribution to our global knowledge of the past distribution of chondrichthyans, being the first well-documented record of the species for the southern hemisphere. Our work shows that future studies are still necessary to better understand the evolutionary history of this shark species in the region.
- Palaeoebiological implications of cuticle morphology, microstructure and formation in modern and fossil Daira (Decapoda, Brachyura, Dairoidea)(2022) Ferratges, Fernando A.; Elorza, Javier; Zamora, SamuelThe origin and function of peculiar mushroom-shaped cuticular structures in some decapod crustaceans remains unknown. This ornamentation has appeared several times in widely disparate clades (in podotreme and heterotreme crabs, and pagurids). These structures are analysed in the modern genus Daira and compared with fossil material from the Eocene of Huesca and the Miocene of Alicante and Mallorca. A morphological and petrographic study is carried out using conventional microscopy and Scanning Electron Microscopy to understand the microstructure in modern and fossil representatives. This provides a clear view of the mushroom-like structures that cover the carapace of Daira and the distribution of the different layers of the exoskeleton. The results reveal a complex morphology, which involves all layers of the cuticle, with changes in the thickness of the exocuticle in different areas, and the presence of conical structures that especially affect the outer layers. These convolutions form a network of channels connected to the outside by pores. Finally, possible anti-predatory functions of these complex structures are proposed.
- Geometric morphometrics of 4D motion data: a proof of concept for applications in palaeoanthropology(2022) Gómez-Recio, Marta; González-Ruíz, José María; Rueda, Javier; San Juan, Alejandro F.; Navarro, Enrique; Beyer, Benoit; Bastir, MarkusThis paper presents a proof of concept in the study of human respiratory motion from a palaeoanthropological approach. The hybrid methodology proposed merges Motion Capture techniques (optoelectronic plethysmography) with 3D geometric morphometrics of the superior torso surface during incremental running exercise. Results reveal the importance of the expiratory phase during high-intensity exercise breathing and arouse a discussion about the structure and function of the respiratory system in human evolution.
- Dinosaur extinctions related to the Jenkyns Event (early Toarcian, Jurassic)(2022) Reolid, Matias; Ruebsam, Wolfgang; Benton, Michael J.The early Toarcian Jenkyns Event (~183 Ma) was characterized by a perturbation of the global carbon cycle, global warming, which at continental areas led to intensified chemical weathering, enhanced soils erosion, and intensified wildfires. Warming and acid rain affected diversity and composition of land plant assemblages, caused a loss of forests and thereby impacted on trophic webs. The Jenkyns Event, triggered by volcanic activity of the Karoo-Ferrar Large Igneous Province, changed terrestrial ecosystems, and also affected the dinosaurs. Fossil macroplant assemblages and palynological data reveal reductions in the diversity and richness of plant communities. A substantial loss of land plant biomass and a shift to forests dominated by Cheiropelidiaceae conifers occurred as a consequence of seasonally dry and warm conditions. Major changes occurred to hervivore dinosaurs, with extinction of diverse basal families of Sauropodomorpha (‘prosauropods’) as well as some basal sauropods. Ornithischian dinosaurs show patchy records; some heterodontosaurids disappeared and the scelidosaurids (Thyreophora) went extinct during the Jenkyns Event. The dominant carnivorous dinosaurs, the Coelophysoidea (Theropoda), died out during the Jenkyns Event. We interpret the Jenkyns Event as a terrestrial crisis for ecosystems, marked especially by floral changes and the extinction of some dinosaur clades, both hervivores and carnivores.
