La mà dels simis, més evolucionada que la dels humans

La mà dels humans és relativament més curta que la dels simis i amb un polze més poderós. L'estudi dels homínids fòssils del Miocè de Catalunya, com Pierolapithecus i Hispanopithecus, juntament amb la d'altres tàxons fòssils d'arreu del món, demostra que els primers homínids tenien mans relativament curtes amb polzes llargs que feien servir per agafar-se de manera segura a les branques dels arbres durant la progressió quadrúpeda i la grimpació vertical. Al contrari del que podria semblar, les mans curtes dels humans no varen derivar a partir de les mans allargades dels actuals grans simis.La mano de los humanos es relativamente más corta que la de los simios y con un pulgar más poderoso. El estudio de los homínidos fósiles del Mioceno de Cataluña, como Pierolapithecus e Hispanopithecus, junto con la de otros taxones fósiles de todas partes del mundo, demuestra que los primeros homínidos tenían manos relativamente cortas con pulgares largos que usaban para cogerse de manera segura a las ramas de los árboles durante la progresión cuadrúpeda y la grimpación vertical. Al contrario de lo que podría parecer, las manos cortas de los humanos no derivaron a partir de las manos alargadas de los actuales grandes simios

Les desconegudes formes de caminar dels goril·les de muntanya

Un estudi internacional amb participació de l'ICP revela que els goril·les de muntanya es desplacen recolzant les mans al terra de formes molt diferents i no només amb els artells, com es creia fins ara. Un 40% dels individus estudiats presentaven formes diferents de recolzament, algunes mai vistes a goril·les. La troballa posa en qüestió el model actual d'evolució del bipedisme en els hominins.Un estudio internacional con participación del ICP revela que los gorilas de montaña se desplazan apoyando las manos en la tierra de formas muy diferentes, y no solo con los nudillos, como se creía hasta ahora. Un 40% de los individuos estudiados presentaban formas diferentes de apoyo, algunas nunca vistas en gorilas. El hallazgo pone en cuestión el modelo actual de evolución del bipedismo en los homínidos

Les adaptacions que ens han fet humans. Morfologia

Altres ajuts: CERCA Programme/Generalitat de CatalunyaEls humans compartim moltes característiques morfològiques amb els grans antropomorfs actuals, però també presentem característiques úniques relacionades amb el bipedisme habitual, la manipulació, la cognició, la dieta, i el comportament sociosexual. Darwin inferí que aquestes característiques estaven relacionades, però no en pogué determinar l'ordre d'aparició. Actualment, les dades moleculars indiquen que els humans i els ximpanzés vam divergir aproximadament fa 9-7 milions d'anys. Però és impossible reconstruir-ne el darrer ancestre comú sense l'ajut del registre fòssil. L'evidència disponible suggereix que era arborícola i tenia un pla corporal ortògrad, unes proporcions de la mà similars a les humanes, i una intel·ligència i una cultura comparables a les dels ximpanzés. Les adaptacions més antigues del llinatge humà estan relacionades amb el bipedisme, la manipulació, i la reducció del dimorfisme sexual. Tanmateix, la majoria d'adaptacions al bipedisme habitual no apareixen fins més tard en els australopitecs. No és fins a l'origen d'Homo que apareixen la majoria d'adaptacions dels humans actuals, relacionades amb l'ús i fabricació habitual d'indústria lítica, el consum de carn, i una cognició més avançada.Humans share many morphological features with living great apes but also display unique characteristics related to habitual bipedalism, manipulation, diet, cognition, and sociosexual behavior. Darwin inferred that all these features were interrelated but could not determine their order of appearance. Currently, molecular data indicate that humans and chimpanzees diverged approximately 9-7 million years ago. However, it is impossible to reconstruct their last common ancestor without the aid of the fossil record. Available evidence suggests that it was arboreal and possessed an orthograde body plan, human-like hand proportions, and chimpanzee-like intelligence and culture. The earliest adaptations of the human lineage are related to bipedalism, manipulation, and a reduction of sexual dimorphism. However, most adaptations to habitual bipedalism do not appear until later in australopiths. It is not until the origin of Homo that most adaptations of extant humans appear, being related to habitual stone tool use and tool making, meat consumption, and more advanced cognition

First record of Latonia gigantea (Anura, Alytidae) from the Iberian Peninsula

The single extant species of the anuran genus Latonia lives in Israel, but in the fossil record the genus is known mainly from Europe, spanning from the Oligocene to the early Pleistocene. Here we describe new remains of Latonia from the early to late Miocene of the Vallès-Penedès Basin (NE Iberian Peninsula), coming from the following localities: Sant Mamet (MN4), Sant Quirze and Trinxera del Ferrocarril (MN7+8), and Castell de Barberà, Can Poncic 1 and Can Llobateres 1 (MN9). Fossils from the late Aragonian and early Vallesian are attributed to Latonia gigantea mainly because of the morphology of the ornamentation that covers the maxillae. In turn, an ilium from Sant Mamet is not diagnostic at the specific level and is assigned only to the genus Latonia. The newly reported remains represent the first record of L. gigantea in the Iberian Peninsula, where Latonia was previously known by a single report of Latonia cf. ragei from Navarrete del Río (MN2) and remains from other localities unassigned to species. Moreover, the Vallès-Penedès remains represent one of the southernmost records of the species known thus far. The presence of Latonia in these localities confirms the humid and warm environment suggested by the recorded mammal fauna

The evolution of human and ape hand proportions

Human hands are distinguished from apes by possessing longer thumbs relative to fingers. However, this simple ape-human dichotomy fails to provide an adequate framework for testing competing hypotheses of human evolution and for reconstructing the morphology of the last common ancestor (LCA) of humans and chimpanzees. We inspect human and ape hand-length proportions using phylogenetically informed morphometric analyses and test alternative models of evolution along the anthropoid tree of life, including fossils like the plesiomorphic ape Proconsul heseloni and the hominins Ardipithecus ramidus and Australopithecus sediba. Our results reveal high levels of hand disparity among modern hominoids, which are explained by different evolutionary processes: autapomorphic evolution in hylobatids (extreme digital and thumb elongation), convergent adaptation between chimpanzees and orangutans (digital elongation) and comparatively little change in gorillas and hominins. The human (and australopith) high thumb-to-digits ratio required little change since the LCA, and was acquired convergently with other highly dexterous anthropoids

12 milions d'anys després, fan un lífting a Pierolapithecus

Un equip de recerca de l'Institut Català de Paleontologia Miquel Crusafont i de l'American Museum of Natural History ha reconstruït la cara del gran antropomorf miocè Pierolapithecus i, a partir d'aquí, ha investigat la història evolutiva de la cara dels hominoïdeus. Els resultats són consistents amb el fet que Pierolapithecus sigui un gran antropomorf basal proper en morfologia facial al darrer ancestre comú dels grans antropomorfs i els humans.Un equipo de investigación del Institut Català de Paleontologia Miquel Crusafont y del American Museum of Natural History ha reconstruido la cara del gran antropomorfo mioceno Pierolapithecus y, a partir de aquí, ha investigado la historia evolutiva de la cara de los hominoideos. Los resultados son consistentes con el hecho que Pierolapithecus sea un gran antropomorfo basal próximo en morfología facial al último ancestro común de los grandes antropomorfos y los humanos.A research team from the Institut Català de Paleontologia Miquel Crusafont and the American Museum of Natural History has reconstructed the face of the Miocene great ape Pierolapithecus and, on its basis, investigates the evolutionary history of the hominoid face. The results are consistent with Pierolapithecus being a basal great ape close in facial morphology with the last common ancestor of great apes and humans

Getting its feet on the ground : elucidating Paralouatta's semi-terrestriality using the virtual morpho-functional toolbox

Altres ajuts: CERCA Programme/Generalitat de CatalunyaCurrently, there are no living platyrrhine primates inhabiting the main Caribbean islands. Nevertheless, the fossil record of this area has provided outstanding findings of different New World monkeys that were part of a diverse radiation exhibiting remarkably unusual morphologies. Among these, the Cuban genus Paralouatta corresponds to one of the most enigmatic primates ever found in the Greater Antilles. Some researchers have argued that Paralouatta's post-cranium shows evidence of semi-terrestriality, a locomotor adaptation that is unusual, if not unique, in platyrrhine evolutionary history. Whether or not Paralouatta was truly semi-terrestrial remains uncertain, however, due to a lack of more sophisticated functional analyses on its morphology. Using novel virtual morpho-functional techniques on a comparative sample of 3D talar models belonging to diverse primate species representing three substrate preferences, this study aims to further evaluate whether Paralouatta was a semi-terrestrial genus or not. Geometric morphometrics and finite element analysis were used to empirically assess shape and biomechanical performance, respectively, and then several machine-learning (ML) classification algorithms were trained using both morphometric and biomechanical data to elucidate the substrate preference of the fossils. The ML algorithms categorized the Paralouatta specimens as either arboreal or as species commonly active on both ground and in trees. These mixed results are suggestive of some level of semi-terrestriality, thus representing the only known example of this locomotor behavior in platyrrhine evolutionary history

Fossil apes and human evolution

Humans diverged from apes (chimpanzees, specifically) toward the end of the Miocene ~9.3 million to 6.5 million years ago. Understanding the origins of the human lineage (hominins) requires reconstructing the morphology, behavior, and environment of the chimpanzee-human last common ancestor. Modern hominoids (that is, humans and apes) share multiple features (for example, an orthograde body plan facilitating upright positional behaviors). However, the fossil record indicates that living hominoids constitute narrow representatives of an ancient radiation of more widely distributed, diverse species, none of which exhibit the entire suite of locomotor adaptations present in the extant relatives. Hence, some modern ape similarities might have evolved in parallel in response to similar selection pressures. Current evidence suggests that hominins originated in Africa from Miocene ape ancestors unlike any living species

Insights into the lower torso in late Miocene hominoid Oreopithecus bambolii

Oreopithecus bambolii (8.3-6.7 million years old) is the latest known hominoid from Europe, dating to approximately the divergence time of the Pan-hominin lineages. Despite being the most complete nonhominin hominoid in the fossil record, the O. bambolii skeleton IGF 11778 has been, for decades, at the center of intense debate regarding the species' locomotor behavior, phylogenetic position, insular paleoenvironment, and utility as a model for early hominin anatomy. Here we investigate features of the IGF 11778 pelvis and lumbar region based on torso preparations and supplemented by other O. bambolii material. We correct several crucial interpretations relating to the IGF 11778 anterior inferior iliac spine and lumbar vertebrae structure and identifications. We find that features of the early hominin Ardipithecus ramidus torso that are argued to have permitted both lordosis and pelvic stabilization during upright walking are not present in O. bambolii. However, O. bambolii also lacks the complete reorganization for torso stiffness seen in extant great apes (i.e., living members of the Hominidae), and is more similar to large hylobatids in certain aspects of torso form. We discuss the major implications of the O. bambolii lower torso anatomy and how O. bambolii informs scenarios of hominoid evolution

Bio- and magnetostratigraphic correlation of the Miocene primate bearing site of Castell de Barber a to the earliest Vallesian

Castell de Barberà, located in the Vallès-Penedès Basin (NE Iberian Peninsula), is one of the few European sites where pliopithecoids (Barberapithecus) and hominoids (cf. Dryopithecus) co-occur. The dating of this Miocene site has proven controversial. A latest Aragonian (MN7+8, ca. 11.88-11.18 Ma) age was long accepted by most authors, despite subsequent reports of hipparionin remains that signaled a Vallesian age. On the latter basis, Castell de Barberà was recently correlated to the early Vallesian (MN9, ca. 11.18-10.3 Ma) on tentative grounds. Uncertainties about the provenance of the Hippotherium material and the lack of magnetostratigraphic data precluded more accurate dating. After decades of inactivity, fieldwork was resumed in 2014-2015 at Castell de Barberà, including the original layer (CB-D) that in the past delivered most of the fossils. Here we report magnetostratigraphic results for the original outcrop and another nearby section. Our results indicate that CB-D is located in a normal polarity magnetozone at about midheight of a short (~20 m-thick) stratigraphic section. The composite magnetostratigraphic section (~50 m) has as many as four to six magnetozones. These multiple reversals, coupled with the in situ recovery of a Hippotherium humerus from CB-D in 2015, make it very unlikely the correlation of any of the sampled normal polarity magnetozones with the long normal polarity subchron C5n.2n (11.056-9.984 Ma), which is characteristic of the early Vallesian. Our results support instead a correlation of CB-D with C5r.1n (11.188-11.146 Ma), where the Aragonian/Vallesian boundary is situated, and therefore indicate an earliest Vallesian age of ~11.2 Ma for Castell de Barberà. Our results settle the longstanding debate about the Aragonian vs. Vallesian age of this site, which appears roughly coeval with the Creu de Conill 20 locality (11.18 Ma), where hipparionins are first recorded in the Vallès- Penedès Basi