Fossil of Early spider Discovered

A team of researchers has discovered the fossil of a 305 million year old arachnid which will help scientist to understand more about the early origins of modern-day spiders. This new species was named Idmonarachne brasieri in honor of professor Martin Brasier, University of Oxford, who passed away in December 2014.

Details of the origins of spiders remain limited with little knowledge of their predecessors and noo insights into character acquisition early in their evolution. This fossil was preserved in 3D, which enabled the researchers to investigate its minutes anatomical details. They could make silk, but probably laid it down in sheets, rather than spinning it as modern spiders do. They also had a tail-like structure at the end called a glagellum. Analysis of Idmonarachne brasieri suggests that as the as the spider lineage evolved, the animals lost their tail-like structure, and developed spider-like fangs limbs. Whilst they could likely make silk, the ancestors lacked the ability to spin it using specialized appendages called spinnerets. These are the features that define true spiders, and give them more control over the use and distribution of silk.

This is part of an ongoing effort to look at early arachnids and see what this can tell us about the early evolution of the group how they came onto land and what their evolutionary tree looks like. Arachnids as a whole are a very diverse group but working out how they are all related to each other has proved a challenge.

Source: Royal Society

Sky Diving Spiders found in S America

Scientists have discovered a type of nocturnal hunting spider in South America, that is able steer while falling. The spider, from the genus Selenops, is the only arachnid that is able to do this. They manoeuvre by spreading their legs in order to use lift and drag to steer themselves towards the tree when they fall. If they fall upside down, they are able to right themselves in midair.

New Dinosaur found from Triassic-Jurassic Period

A new herbivorous dinosaur species, Sefapanosaurus zastronensis, has been found in the the Elliot formation of South Africa.

This report published on 23rd June 2015, in the zoological Journal of the Linnean Society.

This Dinosaur is a herbivore form the southern regions of Gondwanaland some 200 million years ago in the late Triassic or Early Jurassic.  

New tropical tree species await discovery

Scientists have raised the estimated number of tropical tree species to at least 40,000 to 53,000. Many tropical tree species risk extinction because of their rarity and restriction to small geographic areas, reaffirming the need for comprehensive, pan-tropical conservation efforts. 

Although scientists could confidently say 'the tropics are diverse,' the answer to 'how diverse' still remains open to speculation. Tropical tree identification is notoriously difficult -- hampered by hard-to-access terrain and the sheer number of rare species. Much of the data came from CTFS-ForestGEO study sites, where standardized pan-tropical survey methods create opportunities to much more accurately guage tropical diversity. By raising the estimated minimum number of tree species in the world, estimates for the number of insect and microbe species associated with tropical trees also increases, placing an even higher premium on protection of these forest ecosystems.
Co-author William Laurance, senior research associate at STRI and distinguished research professor at James Cook University, explains that the 'stunningly high tree diversity' of the tropics is represented by thousands of rare species, whose sparse populations may not be sustained in the long term by isolated protected areas. This study once again validates a strategy of making forest reserves as big as possible, and also trying to prevent their isolation from adjoining areas of forest.'
The study's lead author Ferry Slik, professor at Universiti Brunei Darussalam, collaborated with over 170 scientists from 126 institutions to study a dataset composed of 207 forested locations across tropical America, Africa and the Indo-Pacific. Each forest plot contains at least 250 individual trees identified to species, ensuring comprehensive coverage of the total species diversity in each geographical area. Among their findings, the researchers note that, contrary to previous assumptions, the Indo-Pacific tropics contain as much species diversity as tropical America -- at least 19,000 species. Both tropical America and the Indo-Pacific are about five times as species-rich as Africa, whose forests are hypothesized to have experienced extensive extinction events during the Pleistocene era of glaciation and climate change. All three regions contain distinct tree lineages reflecting unique evolutionary histories.
Researchers note that their calculations excluded some 10 percent of unidentifiable trees in a dataset comprising 657,630 individuals. Since these trees could reasonably represent rare or previously unknown species, there's a high likelihood that the world's estimates of total tree species diversity will keep increasing as more of the tropics are surveyed and studied. Laurance notes that the CTFS-ForestGEO network continues to grow, adding new forest plots not just for basic research but also, 'as barometers of the long-term effects of global change on forest communities.'
Meanwhile, as deforestation and development increase the extinction risk for many unique species, lessons may be learned from Africa's reduced tropical diversity. When forest areas shrink, rare species are usually the first to disappear. Consequently, even if the extinction pressure is eventually lifted, a much more limited palette of species remains to repopulate the region. While the tropics are vast and diverse, their individual components are irreplaceable.

This story is taken from Science Daily

Seven new miniaturized frog species found in the Brazilian Atlantic Rainforest

Following nearly five years of exploration in mountainous areas of the southern Brazilian Atlantic Rainforest, a team of researchers has uncovered seven new species of a highly miniaturized, brightly colored frog genus known as Brachycephalus. Each species is remarkably endemic, being restricted to cloud forests in one or a few adjacent mountaintops, thus making them highly vulnerable to extinction, particularly due to shifts in the distribution of cloud forest due to climate change. 

The Atlantic Rainforest of Brazil harbors a highly unique group of frogs that have intrigued naturalists for over a century. Known as Brachycephalus, these frogs are among the smallest terrestrial vertebrates, with adult sizes often not exceeding 1 cm in length, leading to a variety of changes in their body structure, such as reduction in the number of toes and fingers. In addition, many species of Brachycephalus are brightly colored, possibly as a warning to the presence of a highly potent neurotoxin in their skin known as tetrodotoxin.
Most species of Brachycephalus are highly endemic, being found exclusively on one, or a few, adjacent mountaintops. Such high levels of endemism is caused by their adaptation to a specific kind of habitat -- the cloud forests -- which simultaneously prevents them from migrating across valleys and promotes the formation of new species.
The first species of Brachycephalus was described in 1842 by the famous German naturalist Johann Baptist von Spix, yet most species in the genus have been discovered only in the past decade, particularly due to their highly endemic nature and the difficulty in reaching remote montane sites. Over the course of five years of fieldwork, a team of researchers has provided the largest addition to the known diversity of Brachycephalus, with seven new species.
"Although getting to many of the field sites is exhausting, there was always the feeling of anticipation and curiosity about what new species could look like," said Marcio Pie, a professor at the Universidade Federal do Paraná, who led the project.
Luiz Ribeiro, a research associate to the Mater Natura Institute for Environmental Studies, is optimistic about the prospects for future studies "This is only the beginning, especially given the fact that we have already found additional species that we are in the process of formally describing."
A major concern regarding the new species is that the same factors that led to their endemism might also be a ticket to their extinction. Cloud forests are highly sensitive to climatic changes, and the long-term preservation of these species might involve not only the protection of their habitats but also more direct management efforts, such as rearing in captivity.

This story is taken from Science Daily