Archaeology News Online

Today mammals and birds are the only true warm-blooded animals. They are called endotherms, meaning they produce their body heat internally. The skeleton of a therapsid dicynodont Lystrosaurus [Credit: Flickr] Endotherm animals are the opposite to ectotherms which get their heat from an external factor like the sun. They are considered “cold-blooded”. The origins of warm-bloodedness in mammals has been a very controversial issue for two reasons. One is that several of the anatomical features thought to be linked to warm-bloodedness have also been found in cold-blooded reptiles. The other is that these characteristics are not always preserved in fossils, giving scientists inconsistent signals about the presence of warm-bloodedness. Our research helps shed new light on this controversy. We’ve been able to come up with new insights about how mammals developed a warm-blooded metabolism that may have helped them survive the terrible mass extinction that marked the end of the Permian period...

Using a combination of fossils and chemical markers, scientists have tracked how a period of globally low ocean-oxygen turned an Early Jurassic marine ecosystem into a stressed community inhabited by only a few species. Before the low oxygen period, bivalves were larger and more numerous [Credit: The University of Texas at Austin/ Rowan Martindale] The research was led by Rowan Martindale, an assistant professor at The University of Texas at Austin Jackson School of Geosciences, and published in print in Palaeogeography, Palaeoclimatology, Palaeoeconology . The study was co-authored by Martin Aberhan, a curator at the Institute for Evolution and Biodiversity Science at the Natural History Museum in Berlin, Germany. The study zeroes in on a recently discovered fossil site in Canada located at Ya Ha Tinda Ranch near Banff National Park in southwest Alberta. The site records fossils of organisms that lived about 183 million years ago during the Early Jurassic in a shallow sea that once co...

The results, which include information during the last glacial and interglacial periods, showed that relief from the current dry spell across the interior of the Middle East is unlikely within the next 10,000 years. Graphs showing data measured from two stalagmites from QK Cave in Iran in comparison with other proxy records.  A: Blue line is δ18Oc from QK14 and green line is QK8. Both are from the same came but ~75m apart from one  another. Primary driver for long scale climate change is orbital configuration.  Colored diamonds represent U-Th  age tie points with their associated error bars. B: Orange line is δ18Ow measured in the NGRIP ice core.  C: Purple line is δ18Oc measured in Sanbao Cave, China, part of the Hulu Cave record (Wang et al., 2008).  D: Dark blue line is δ18Oc measured in Soreq Cave, Israel (Bar-Matthews et al., 2003). E: Light blue line is δ18Oc measured in foraminifera collected from deep sea sediment cores (Lisiecki et al., 2005) ...

A peat bog in Romania provides a new insight into our knowledge of when the Sahara began to transform from grassland into the desert we know today, and the impact this had on dust deposition within Eastern Europe. Saharan dust over the Mediterranean Sea [Credit: Northumbria University] Using carbon dating and chemical analysis, researchers from Northumbria University, Newcastle have shown that significant changes in dust levels occurred in Romania around 6,100 years ago, despite the climate in Eastern Europe being relatively wet at this time, indicative of an extraregional source of such dust, most likely to be from the Sahara. This discovery is valuable new evidence of the impact changes in the climate and vegetation of North Africa may have on dust in Europe and may allow climate modellers to better understand the movement of dust and the impact of desertification, both in the past and the future. The research was led by Jack Longman, a Geography PhD student at Northumbria. His resul...

Climate evolution shows some regularities, which can be traced throughout long periods of earth's history. One of them is that the global average temperature and the carbon dioxide concentration in the atmosphere usually go hand-in-hand. To put it simple: If the temperatures decline, the CO2 values also decrease and vice versa. Model of an island volcano. During the last transition to glacial conditions the decreasing pressure  at the seafloor could have induced increased lava- and carbon dioxide emissions  [Credit: Jorg Hasenclever] However, there are exceptions. An international team of scientists led by the GEOMAR Helmholtz Centre for Ocean Research Kiel and the Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research has now discovered a possible cause for such irregularities. An example is the last transition to glacial conditions. At approximately 80,000 years ago the temperatures declined, but the amount of carbon dioxide in the atmosphere remained relati...

Today mammals and birds are the only true warm-blooded animals. They are called endotherms, meaning they produce their body heat internally. The skeleton of a therapsid dicynodont Lystrosaurus [Credit: Flickr] Endotherm animals are the opposite to ectotherms which get their heat from an external factor like the sun. They are considered “cold-blooded”. The origins of warm-bloodedness in mammals has been a very controversial issue for two reasons. One is that several of the anatomical features thought to be linked to warm-bloodedness have also been found in cold-blooded reptiles. The other is that these characteristics are not always preserved in fossils, giving scientists inconsistent signals about the presence of warm-bloodedness. Our research helps shed new light on this controversy. We’ve been able to come up with new insights about how mammals developed a warm-blooded metabolism that may have helped them survive the terrible mass extinction that marked the end of the Per...

Using a combination of fossils and chemical markers, scientists have tracked how a period of globally low ocean-oxygen turned an Early Jurassic marine ecosystem into a stressed community inhabited by only a few species. Before the low oxygen period, bivalves were larger and more numerous [Credit: The University of Texas at Austin/ Rowan Martindale] The research was led by Rowan Martindale, an assistant professor at The University of Texas at Austin Jackson School of Geosciences, and published in print in Palaeogeography, Palaeoclimatology, Palaeoeconology . The study was co-authored by Martin Aberhan, a curator at the Institute for Evolution and Biodiversity Science at the Natural History Museum in Berlin, Germany. The study zeroes in on a recently discovered fossil site in Canada located at Ya Ha Tinda Ranch near Banff National Park in southwest Alberta. The site records fossils of organisms that lived about 183 million years ago during the Early Jurassic in a shallow sea that once co...