geological-time

vine

Clouds rolling over sharp peaks in the Swiss Alps.

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About Grass

Grass: Kingdom Plantae, Order Poales, Family Poaceae

Grasses exhibit some of the highest diversity in the plant kingdom. They spread across the globe near the end of the Cretaceous period, some 66 million years ago, as evidenced by fossilized dinosaur dung (coprolites). Different grasses have adapted to essentially all habitates on earth from rain forests, arid deserts, cold mountains and intertidal ecosystems.

The upper image is a field of wet grass, and the lower, grass flowers.

An Entangled Bank Geologic Time

vine

Flowering plants (angiosperms) appear fairly late in geologic time, during the time of dinosaurs some 120 million years ago in the Cretaceous. They are now the dominant plant type with some 0.3 million species known. Symbiosis (mutualism) and co-evolution is common across the tree of life, and bees and angiosperm have a real cozy co-dependence - the bees get food, and the plants get sex. 

Was Our Planet Really Once a Hell on Earth?

For the first 500 million years of its existence, our planet was believed to literally be a hell on Earth. But new research shows that this early Earth may have been surprisingly similar to the present day, complete with oceans, continents and active crustal plates.

This alternate view of Earth’s first geologic eon, called the Hadean, is based on a comparison of zircon crystals formed four billion years ago with those formed during the same time period in Iceland. This icy country is supposedly what early Earth geological conditions were like, and so serves as a sort of blueprint for scientists studying the beginnings of our planet.

“We reasoned that the only concrete evidence for what the Hadean was like came from the only known survivors: zircon crystals – and yet no one had investigated Icelandic zircon to compare their telltale compositions to those that are more than 4 billion years old, or with zircon from other modern environments,” lead researcher Calvin Miller of Vanderbilt University said in a statement.

Until 30 years ago, scientists thought the Hadean period was hellishly hot, and Earth was covered by a giant “magma ocean.” This view was based on the fact that they could never find rock formations from that time period, jumping to the conclusion that the intense heat melted the rocks, leaving behind no trace.

But then geologists discovered zircon crystals - a mineral typically associated with granite - preserved in younger sandstones. Radiometric dating and other analytical techniques allowed the researchers to study early Earth’s crust via these four-billion-year-old crystals, as well as extract information about the environment in which the crystals formed, including the temperature and whether water was present.

And after comparing these crystals with about 1,000 ancient zircons sifted from volcano and sand samples off Iceland, the researchers found that Icelandic zircons grew from much hotter magmas than Hadean zircons.

Despite the assumption that Earth was insanely hot, their analysis revealed that at some points during the Hadean period Earth’s crust cooled enough so that surface water could form - possibly on the scale of oceans.

“Our conclusion is counterintuitive,” said Miller. “Hadean zircons grew from magmas rather similar to those formed in modern subduction zones, but apparently even ‘cooler’ and 'wetter’ than those being produced today.”

The findings were published in the journal Earth and Planetary Science Letters.

Have we entered a new geologic time epoch? Some scientists think so

According to the working group on the Anthropocene:

  • The ‘Anthropocene’ is a term widely used since its coining by Paul Crutzen and Eugene Stoermer in 2000 to denote the present time interval, in which many geologically significant conditions and processes are profoundly altered by human activities. These include changes in: erosion and sediment transport associated with a variety of anthropogenic processes, including colonization, agriculture, urbanisation and global warming. the chemical composition of the atmosphere, oceans and soils, with significant anthropogenic perturbations of the cycles of elements such as carbon, nitrogen, phosphorus and various metals. environmental conditions generated by these perturbations; these include global warming, ocean acidification and spreading oceanic 'dead zones’. the biosphere both on land and in the sea, as a result of habitat loss, predation, species invasions and the physical and chemical changes noted above.
  • The 'Anthropocene’ is not a formally defined geological unit within the Geological Time Scale. A proposal to formalize the 'Anthropocene’ is being developed by the 'Anthropocene’ Working Group for consideration by the International Commission on Stratigraphy, with a current target date of 2016. Care should be taken to distinguish the concept of an 'Anthropocene’ from the previously used term Anthropogene (cf. below**).
  • The 'Anthropocene’ is currently being considered by the Working Group as a potential geological epoch, i.e. at the same hierarchical level as the Pleistocene and Holocene epochs, with the implication that it is within the Quaternary Period, but that the Holocene has terminated. It might, alternatively, also be considered at a lower (Age) hierarchical level; that would imply it is a subdivision of the ongoing Holocene Epoch.
  • Broadly, to be accepted as a formal term the 'Anthropocene’ needs to be (a) scientifically justified (i.e. the 'geological signal’ currently being produced in strata now forming must be sufficiently large, clear and distinctive) and (b) useful as a formal term to the scientific community. In terms of (b), the currently informal term 'Anthropocene’ has already proven to be very useful to the global change research community and thus will continue to be used, but it remains to be determined whether formalisation within the Geological Time Scale would make it more useful or broaden its usefulness to other scientific communities, such as the geological community.
  • The beginning of the 'Anthropocene’ is most generally considered to be at c. 1800 CE, around the beginning of the Industrial Revolution in Europe (Crutzen’s original suggestion); other potential candidates for time boundaries have been suggested, at both earlier dates (within or even before the Holocene) or later (e.g. at the start of the nuclear age). A formal 'Anthropocene’ might be defined either with reference to a particular point within a stratal section, that is, a Global Stratigraphic Section and Point (GSSP), colloquially known as a 'golden spike; or, by a designated time boundary (a Global Standard Stratigraphic Age).
  • The 'Anthropocene’ has emerged as a popular scientific term used by scientists, the scientifically engaged public and the media to designate the period of Earth’s history during which humans have a decisive influence on the state, dynamics and future of the Earth system. It is widely agreed that the Earth is currently in this state.

An Entangled Bank Geologic Time

Beautiful Tanzanite

I don’t think I’ve ever seen as rich a blue in a zoisite as this 10 cm specimen on matrix from the Merelani hills of Tanzania. While it has almost certainly been heated to bring out the colour (natural blues only happen when heat has been an immediate part of their geological adventure through deep time), the depth of saturation (pink for example is a light red) and perfection of tone (neither too light or dark) make this a gem to be admired. We covered the mineral in greater depth before at http://tinyurl.com/m2kotqd

Loz

Image credit: Malte Sickinger

Oricorio Origins

SO. I am very excited about this new birdo pokemon. Oricorio are based on the Hawaiian Honeycreepers, which are the Hawaiian equivalent of Darwin’s Finches, but oh so much better. We all know about Darwin’s finches of the Galapagos (see below), who, from single ancestor rapidly evolved and radiated into a variety of new species all with different beak types to exploit different niches, i.e. different food types, in a process called adaptive radiation.

Different species are found on different islands, corresponding to different food types and niches available. There are about 14 species of Darwin’s Finch, which is pretty impressive from one single ancestor in a relatively short amount of geological time. 

So what about these Honeycreepers? Well, historically it is thought that there were 51 species of Hawaiian honeycreeper, found only on the Hawaiian Archipelago, deriving from one common ancestor, and giving one of the most impressive examples of the extent of insular adaptive radiation known, putting Darwin’s finches to shame. (here are just some below)

The range of beak types seen is simply astonishing, exploiting a huge range of food types and diets. Oricorio specifically appear to be based on the Drepanidini honeycreepers, the group that specialises in feeding on nectar, and which also have some of the brightest coloured plumage. The beaks of different species have co-evolved with specific flowers. For example the I’iwi, a well known symbol of Hawaii, has a long curved beak to feed on the thin curved flowers of Hawaiian Lobelioid plants. (I think it really looks like the Baile style Oricorio!)

As the new SM info states, different forms (or species/subspecies) of Oricorio are found on different Alolan Islands, much as different Hawaiian islands will hold different Honeycreeper species, often based on a varying food source, for example, flower species. 

Unfortunately there is a sad side to all this. Note how I said earlier that historically there have been 51 honeycreeper species. Thanks to habitat destruction, predation by introduced non-native species (mainly mammals, such as feral cats and mongoose, litten and yungoos cough cough), competition from non-native birds, avian malaria, and a variety of other human mediated factors, less than half of those species still exist today, and many of those are highly endangered and near extinction. Even the I’iwi, once common, has seen a highly drastic decline in recent decades. 

You can donate to an I’iwi and other Honeycreeper conservation and forest recovery project on Maui Island here

Take a tour of fossils across geologic time and evolution

A tour of life over geologic time and evolution as evidenced by the fossil record:

Precambrian Fossils I Cambrian Fossils I Ordovician Fossils I Silurian Fossils I Devonian Fossils I Carboniferous Fossils I Permian Fossils I Triassic Fossils I Jurassic Fossils I Cretaceous Fossils I Tertiary Fossils


Also see:

Yannanozoon lividum, Putative Earliest Known Hemichordate from the Chengjiang Biota

“a fossil of the Cambrian Explosion from Yunnan Province, China”

Yannanozoon lividum 

Phylum Hemichordata
Geological Time: Early Cambrian (~525 million years ago)
Size: 23 mm long on a 75 mm by 65 mm matrix
Fossil Site: Chengjiang Maotianshan Hill, Quiongzhusi Section, Yu'anshan Member, Heilinpu FormationYuxi, Chengjiang County, Yunnan Province, China

Yannanozoon bear resemblance and traits to Haikouella lanceolata, a chordate from the same Maotianshan Shales.

Continue reading  …

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If Jurassic Park had instead chosen different geologic eras

The Hidden Life of trees: What they Feel, How they Communicate

While I have long loved forests in all their forms, I had never understood them as deep a way until this book enriched me, giving me as close to an inside perspective on what life as a tree might be like as I’m likely to get. Written by a forester with over 30 years experience managing a communal forest in Germany, the first thing it taught me to do was to slow down my perspective on time, and perceive what life lived at a very different rhythm and in vastly varying constraints must be like. Unlike the events of deep geological time, trees still change on a human scale while remaining able to live for several millennia. The tree your grandfather planted remains but a youngster.

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