News Article | November 7, 2016
Ancient feeding marks from hungry insects in South American leaf fossils are shedding new light on the mass extinction that wiped out the dinosaurs. Scientists analyzed insect feeding damage to thousands of leaf fossils from Patagonia, Argentina, over the Cretaceous-Paleogene boundary, and found evidence that ecosystems there recovered twice as fast as in the United States. The findings, published today (Nov. 7) in the new journal Nature Ecology & Evolution, offer important evidence of how terrestrial ecosystems outside the U.S. responded after an asteroid struck Chicxulub, Mexico, some 66 million years ago, marking the end of the Cretaceous period. "Most of what we know about terrestrial recovery comes from the western interior United States, relatively close to the Chicxulub crater, which has limited our knowledge of recovery in the rest of the world," said Michael Donovan, doctoral student in geosciences, Penn State and lead author on the paper. "We are giving another view of what was happening during that time, far away from the impact site." Donovan and his international team found leaf-mining insects completely disappeared in Patagonia during the extinction event, as previous studies show happened in the U.S. But unlike the U.S., where it took 9 million years to return to pre-impact insect diversity, recovery happened in just 4 million years in Patagonia. "Insects and plants are the most diverse multicellular organisms in the world, and they are known to respond to major environmental changes," Donovan said. "So they make a great resource to study our past." The team analyzed 3,646 fossils from Patagonia searching for signs of leaf miners -- insect larvae named for the type of damage they cause tunneling though leaves for food. These feeding paths, and the insects' droppings, both create distinctive patterns and can be compared among fossils at different sites. "Michael developed this technique of very detailed examination of leaf miners, and new methods for looking at the critical differences among these feeding trails in fossil leaves," said Peter Wilf, professor of geosciences, Penn State and paper co-author. "He's teased apart this huge story from the tiny differences in how baby insects did their business in leaves that lived 66 million years ago." The scientists found no evidence that individual leaf miner species from the Cretaceous survived the extinction event in Patagonia, indicating the far south did not offer a refuge for the insects as Donovan's team first hypothesized. "There was no evidence of survival, which is similar to what I found when working on my master's research at the Mexican Hat site in Montana," Donovan said. "But what we do find in Patagonia is a pretty diverse group of novel leaf miners that appear much sooner than in the western U.S." The researchers suggested Patagonia's further distance from the impact crater in Mexico and its ground zero effects could be responsible for insect diversity returning more rapidly to the southern location. "The richness of plant-insect associations that we observed during the recovery may be a contributing factor to insect biodiversity in modern South America," Donovan said. "We can look far into the past and see these patterns that influence life on Earth as it is today." Wilf said the study, the first of its kind outside the western U.S., can help scientists answer questions about modern global biodiversity. "Our modern world is the legacy of this disaster," Wilf said. "As we try to understand how today's biodiversity evolved and why Earth's millions of species live where they do, the global impact of this major catastrophe is a big sleeping elephant in a dark room -- we can't see much of it and just don't know enough about it. As we turn on the lights, we see more of the elephant and understand our world better. This paper is a welcome step in that direction." Other researchers on this project were Ari Iglesias, Universidad Nacional del Comahue, Argentina; Conrad C. Labandeira, National Museum of Natural History, the Smithsonian Institution; and N. Ruben Cuneo, Museo Paleontologico Egidio Feruglio, Trelew, Argentina.
Onset of the Middle Eocene global cooling and expansion of open-vegetation habitats in central Patagonia [Inicio del enfriamiento global del eoceno medio y expansión de ambientes con vegetación abierta en la Patagonia central]
Bellosi E.S.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia |
Krause J.M.,Museo Paleontologico Egidio Feruglio
Andean Geology | Year: 2014
Climate-driven changes in terrestrial environments and biomes after the Early Eocene Climatic Optimum are poorly documented from southern continents. Particularly, Middle Eocene-Early Oligocene leaf and pollen data from Central Patagonia (46oS, Argentina) are not sufficient to characterize floristic paleocommunities. Paleosols of the Cañadón Vaca (~45-42 Ma) and Gran Barranca (42-38.5 Ma) members (Sarmiento Formation), studied at Cañadón Vaca, solve such deficiency and help to reconstruct Middle Eocene landscapes in the beginning of the Cenozoic cooling-drying trend. Vitric Entisols, mollic Andisols and andic Alfisols, showing granular structure and diverse micropeds, are cyclically arranged mainly in response to variation in fine volcaniclastic eolian supply, which in turn governed ecosystem stability and maturity. Soils formed in loessic plains crossed by minor ephemeral rivers, supported open herbaceous-arboreal communities which grew in seasonal, subhumid and warm-temperate conditions. Phytoliths produced by Arecaceae, megathermic graminoids, sedges and dicots, from the upper part of the studied unit, represent subtropical savannas with grasses and variable number of palms and other trees. Considering the abundant paleobotanical and paleopedological antecedents of Late Paleocene-Early Eocene warm and humid forested environments in the same region, the lower Sarmiento Formation records the initial expansion of open herbaceous communities and the appearance of grassy habitats during the greenhouse to icehouse transition in the Middle Eocene.
Ezcurra M.D.,Museo Argentino de Ciencias Naturales Bernardino Rivadavia |
Lecuona A.,Museo Paleontologico Egidio Feruglio |
Martinelli A.,Federal University of Uberlandia
Journal of Vertebrate Paleontology | Year: 2010
The best-known South American Early Triassic archosauriform belongs to a putative proterosuchid briefly reported by Jos Bonaparte in 1981, collected from the Quebrada de los Fsiles Formation (Puesto Viejo Group, Argentina). This specimen consists of well-preserved natural external molds of a partial postcranium that preserve dorsal vertebrae, osteoderms, a dorsal rib, a possible gastralium, a chevron, a humerus, an ilium, two metapodials, and an ungual. We re-describe this specimen and identify autapomorphies that allow us to recognize Koilamasuchus gonzalezdiazi, gen. et sp. nov. The presence of an iliac blade with a slightly convex dorsal margin and with a maximum length more than 3 times its maximum height places Koilamasuchus within Archosauriformes. A cladistic analysis of basal Archosauriformes positions Koilamasuchus more crownwards than Proterosuchus, Sarmatosuchus, Fugusuchus, and Osmolskina, as the sister taxon of the clade that includes Erythrosuchidae and Archosauria. Proterosuchidae is found to be paraphyletic. The presence of an iliac preacetabular process, a pubic peduncle that forms an angle lower than 45° to the longitudinal axis of the ilium, and dorsal body osteoderms positions Koilamasuchus in Archosauriformes more crownwards than proterosuchids. Koilamasuchus is more basal than erythrosuchids within Archosauriformes because of the presence of dorsal ribs with a poorly developed proximal end. Koilamasuchus importantly increases the diversity of Archosauriformes during the biotic recovery following the Permo-Triassic mass extinction. © 2010 by the Society of Vertebrate Paleontology.
News Article | January 15, 2016
Meet the Titanosaur, one of the world's biggest dinosaur discovered so far, and currently in display in the United States. The 122-foot-long and 140,000-pound dinosaur was unearthed in Patagonia. Its size is equal to almost 10 African elephants. The American Museum of Natural History in Manhattan, New York unveiled what may be the world's biggest dinosaur in an advanced viewing on Thursday. Simply dubbed Titanosaur, the paleontologists who unearthed the giant have not yet found a scientific name for it. Its full unveiling and launch will be held today. Instead of occupying one room, it is housed in a two rooms that have 19-foot-high ceilings. But the Titanosaur is so big, its 39-foot-long neck still sticks out of the exhibition space, with its head craning beyond the entrance, as if to stare or perhaps greet museum visitors. "At 122-foot, is just a bit too long for its new home. Instead, its neck and head extend out towards the elevator banks, welcoming visitors to the "dinosaur" floor," the museum said. "One femur found at the excavation site will be among five original fossils on temporary view with The Titanosaur," it added. The other fossils found at the site are the dinosaur's humerus, ulna, radius and scapula, which are all on temporary display. The species lived in the forests of what people know today as Patagonia in Argentina about 100 to 95 million years ago. The Titanosaur was known to have lived during the Late Cretaceous period. A team from the Museo Paleontologico Egidio Feruglio, led by José Luis Carballido and Diego Pol, unearthed the fossils of the gigantic dinosaur in Argentina in 2014. Scientists have long been exploring Argentina to track down Titanosaurs, which is a large sauropod among the last dinosaurs to walk the Earth. Much of the scientific evidence shows that the Titanosaur is one of the large herbivores that have roamed Earth millions of years ago. At present, an exploration of possible resting places of this species is still ongoing. Will they find another Titanosaur bigger than the one on display in the museum?
Perez M.E.,Museo Paleontologico Egidio Feruglio |
Journal of Vertebrate Paleontology | Year: 2010
Cavioidea sensu stricto groups three traditionally recognized families that are characterized by hypsodont, double-heart-shaped cheek teeth and moderate hystricognathy: Eocardiidae, Caviidae, and Hydrochoeridae. Eocardiidae was erected to include a diverse assemblage of extinct and plesiomorphic taxa, whereas Caviidae and Hydrochoeridae (the crown group of Cavioidea) include the lineages with extant representatives (cuyes, maras, and capybaras). A new genus and species of Cavioidea sensu stricto, Guiomys unica, is described here from the middle Miocene of west central Patagonia (Argentina). The new taxon is known from mandibular and maxillary fragments with molars, and isolated cheek teeth. A phylogenetic analysis of Cavioidea sensu stricto shows G. unica as the sister taxon of the clade formed by the crown group of Cavioidea sensu stricto ('medialis series'). The new species displays characters states intermediate between eocardiids and the 'medialis series.' The most outstanding character of Guiomys unica is the autapomorphic position of the notch for the insertion of the masseter medialis pars infraorbitalis muscle, isolated from both the masseteric and horizontal crests. This notch is located at the anterior end of the masseteric crest in eocardiids and represents the plesiomorphic state for Cavioidea sensu stricto. In caviids and hydrochoerids, the notch is located at the anterior end of the horizontal crest, the derived state for this character. G. unica allows reinterpretation of the homologies of the mandibular crests in basal cavioids and clarifies the evolutionary origins of crown-group cavioids (Caviidae + Hydrochoeridae). © 2010 by the Society of Vertebrate Paleontology.
Ferrari S.M.,Museo Paleontologico Egidio Feruglio |
Journal of Systematic Palaeontology | Year: 2014
Gastropods are represented in the Early Jurassic of Argentina by Vetigastropoda, Caenogastropoda and Opisthobranchia. The present paper describes nine new vetigastropod species from the Early Jurassic marine deposits of the Neuquén Basin: Proconulus? argentinus sp. nov., Chartronella atuelensis sp. nov., Striatoconulus? axialis sp. nov., Guidonia disciformis sp. nov., Ambercyclus andinus sp. nov., Ambercyclus chilcaensis sp. nov., Discohelix sanicoensis sp. nov., Cryptaenia sudamericana sp. nov. and Cryptaenia globosa sp. nov. Another three vetigastropods are reported for the first time in this region – Chartronella gradata Ferrari, Ataphrus mulanguiniensis Ferrari and Colpomphalus? aff. musacchioi Ferrari – extending their palaeobiogeographical distributions in the Andean region of Argentina. Lithotrochus humboldtii (von Buch), Lithotrochus rothi Damborenea & Ferrari, and an undetermined ataphrid species were also retrieved from marine beds of the Neuquén Basin. A quantitative palaeobiogeographical analysis was performed integrating available data on the entire marine vetigastropod species thus far recorded from Argentina. The primary results of the analysis show two clearly discernible palaeobiogeographical units in the Andean region of Argentina. The local vetigastropod species from the Neuquén and Chubut basins may be interpreted considering palaeogeographical control as a determinant in the distribution of these taxa, including the separate evolution of the Neuquén basin until the late Pliensbachian. However, a shallow marine connection between the Neuquén and Chubut basins along the Palaeo-Pacific seaway during the late Pliensbachian–early Toarcian may explain faunal exchange between both basins at that time.http://zoobank.org/urn:lsid:zoobank.org:pub:EBB37780-8571-4B02-9424-A32E1C2A9AC9 © The Trustees of the Natural History Museum, London 2014. All Rights Reserved.
Perez Loinaze V.S.,CONICET |
Archangelsky S.,CONICET |
Cladera G.,Museo Paleontologico Egidio Feruglio
Cretaceous Research | Year: 2012
Palynomorph assemblages have been recovered from the upper levels of the Río Mayer Formation and the basal levels of the Kachaike Formation exposed at the Puesto El Moro Creek, southwest of Santa Cruz Province, Argentina. Forty-five spore species and 25 pollen taxa (including six angiosperms) have been identified. The palynological assemblages of the upper levels of Río Mayer Formation are dominated by pteridophytic spores, while Classopollis is a common element. In the Kachaike Formation, the angiosperm pollen grains are more diverse and abundant than in the underlying unit, and Cheirolepidiaceae pollen continues to dominate. The presence of scarce angiosperm pollen, represented by Clavatipollenites sp., allows reference of the assemblage recorded in the upper levels of the Río Mayer Formation to the Aptian Antulsporites- Clavatipollenites Zone. In addition, the lower levels of the Kachaike Formation are referred to the late Aptian-early Albian, based on the presence of Asteropollis asteroides, Pennipollis peroreticulatus, Clavatipollenites sp. and scarce tricolpate pollen. From the three major stages of the early angiosperm evolution in southern South America that have been previously recognized, the palynoflora of the upper levels of the Río Mayer Formation can be referred to Stage I (late Barremian-Aptian), whereas the assemblages recognized in the Kachaike strata are comparable to Stage II (latest Aptian- earliest Albian). © 2011 Elsevier Ltd.
Gambino P.,Museo Paleontologico Egidio Feruglio |
Industrial Crops and Products | Year: 2011
Wild evening primrose species (Oenothera spp.) native to Argentina, have been suggested as a new crop for irrigated valleys of semi-arid Patagonia. This paper describes patterns of biomass allocation, morphological traits related to stress-tolerance and seed-yield in four species of Oenothera grown in a common garden at three plant densities. Wild and domesticated species are compared. The effect of resource availability on those traits during three phenological stages (vegetative, reproductive and maturity) is described. Native species were characterized by traits related to stress-tolerance (high root allocation and low specific leaf area) during the vegetative stage. This suite of traits resulted in low biomass accumulation and low seed-yield. The domesticated O. biennis was characterized by a combination of traits related to stress-tolerance (low specific leaf area) and high productivity (high leaf allocation and leaf area ratio and low root allocation). Domesticated species accumulated more biomass than natives. Total biomass and total non-structural carbohydrates present in roots were positively correlated to seed-yield.Oenothera biennis showed the highest seed-yield, although this species showed yield instability in response to changes in the environmental quality. No changes in seed-yield in response to plant density were recorded for either O. lamarckiana or native species. Oenothera biennis showed an optimum density of 20plantsm-2 and yielded 260gm-2, a seed-yield similar to that reported in other countries. Low seed-yield of native species is major drawback that must be overcome. Improving seed-yield in these species could be possible by selection oriented to increase total biomass. Since no detrimental effect of density was found in O. lamarckiana and natives, a higher plant density might increase yield production per unit area. © 2010 Elsevier B.V.
Perez M.E.,Museo Paleontologico Egidio Feruglio |
Vucetich M.G.,Museo de La Plata
Journal of Mammalian Evolution | Year: 2011
The family Caviidae is represented in modern faunas by cavies and maras, whereas the family Hydrochoeridae is represented by capybaras. The evolutionary origin of these families has been related to a diversity of plesiomorphic fossil forms (recorded from the late Oligocene up to the middle Miocene) traditionally grouped in the family "Eocardiidae". These fossil forms were included, together with Caviidae and Hydrochoeridae, within the Cavioidea s. s. (sensu stricto), because they share high crowned cheek teeth, double-hearted occlusal surface, short lower incisors, and moderate hystricognathy. Within Cavioidea s. s., caviids and hydrochoerids were interpreted as forming its crown group, because they have unique craniomandibular and dental features. In this contribution, a new taxon of Cavioidea s. s. from the middle Miocene of central Patagonia, Argentina, is described, and its phylogenetic position is determined on the basis of a morphological cladistic analysis in which "eocardiids" were included. The study permits the understanding of the sequence of appearance of characters that originated the highly divergent morphology of crown-group cavioids. The analysis of the sequence of appearance of the characters that traditionally diagnosed the crown group indicates that these changes did not occur at the same time. On the contrary, many of these features seem to have appeared at different nodes of the evolutionary history of Cavioidea s. s. The remarkably derived morphology of modern cavioids is the result of a stepwise appearance of a mosaic of evolutionary innovations that originated gradually along the history of Cavioidea during the late-middle Miocene. © 2011 Springer Science+Business Media, LLC.
Ferrari S.M.,Museo Paleontologico Egidio Feruglio
Alcheringa | Year: 2012
New species of Cryptaulax and Procerithium (Procerithiidae, Caenogastropoda) are reported from the Lower Jurassic (Pliensbachian-Toarcian) marine deposits of west-central Chubut province, Argentinean Patagonia. Three new species are described: Cryptaulax redelii, Procerithium (Rhabdocolpus) patagoniensis and Procerithium (Infacerithum) nodosum; and the diagnoses of Cryptaulax damboreneae Ferrari and Procerithium nulloi (Ferrari) are emended. The new fossils derive from the Mulanguiñeu and Osta Arena formations and expand the known diversity of the Procerithiidae, extending its palaeobioeographical distribution into the South American Jurassic. © 2012 Copyright Taylor and Francis Group, LLC.