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#silurian

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Planetary Ecologist

Silurian (Geological periods 🌍)

The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago, to the beginning of the Devonian Period, 419.2 Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a...

en.wikipedia.org/wiki/Silurian

#Silurian#GeologicalPeriods
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Chris White

When (micro)continents collide

#Silurian or #Devonian #metasediments / pellitic #schists / sulfidic schists
North Pack Monadnock, south central New Hampshire USA

Intensely folded rocks

Merrimack / Central Maine Trough smashed as #Avalonia joined Laurasia to start assembling Pangea in the #Acadian #Orogeny, about 375 million years ago.

Knowing some #geology makes hiking more fun!

Normally proportioned geochemist forelimb for scale
My #photo
Fujifilm X-H1 16 mm f/1.4 @ f/4 ⅛ s ISO 200 (IBIS)

The image is a color digital photograph 2 wide by 3 high. A finger is pointing to hard, tightly folded metamorphic rocks, which ripple across the frame.
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Mike Roberts

Visited a friend over the weekend for a bit of help diagnosing an old Dalek voice board and he showed me the Radio Control Trilobites he has been upgrading for his local Geological society. They can zoom around at quite a pace and are great for engaging kids at events. That and they look amazing 😄
They are "Dudley Bug" or Calymene Blumenbachi from the Silurian period ~428 million years old I am told.
#trilobite #rc #silurian #dudleybug #geology

A large scaled up trilobite model sits on top of some sheets of A4 paper. It almost covers the page. It is brown in colour.
Two Trilobites are turned over on to their backs. Where, on a real creature, there would be a feast of scuttling legs, there is a small remote control car chassis screwed in to a hollow in the underside. It has steering, 2 drive wheels and a battery compartment built in to the black plastic chassis.
Continued thread
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Vickysaurus

#Silurian

Although fungi and bacteria had already made forays onto the land deep in the past, things began to get busier there in the Silurian. But these horseshoe crabs, and their larger cousins the sea scorpions, have not come to the shore to stay, but to mate and lay eggs. Unfortunately for the horseshoe crabs, they have come to the very same shore.

#paleoart

(5/14)

A watercolour showing a calm beach at night. Pseudoniscus horseshoe crabs are crowded around one another and mating in the shallows in the foreground, partially underwater and partially about it. They looks similar to modern horseshoe crabs, but the segments on the rear half of their body are not fused into an extension of the carapace. Two of them have been flipped onto their backs and are struggling to right themselves. Farther in the background, the much larger sea scorpions are doing similar things. They resemble scorpions, but with the tail held flat and large swimming paddles instead of claws. One of them has noticed the horseshoe crabs and is chasing one. There are shells on the moonlit beach and small dunes with Cooksonia plants past them. They are primitive plants whose stalks split in two several times and end in a cup-shaped sporangium. There are stars in the sky and reflections of moonlight on the water and the animals, though the Moon itself is not seen.
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DailyMegafauna

Today's #mega...er... organisms...are prototaxites. These large, columnar fossils date to 240-350 million years, and stood 24 feet tall and 3 feet wide when they were alive. During this time period, both plants and animals on land were still quite small--meaning that #prototaxites formed the dominant feature of the land during the #Silurian and #Devonian periods.

But what exactly were these giant spires? First described in 1859, they were originally thought to be very early trees. However, their internal structure of tiny, criss-crossing tubes suggests that this is not correct. Chemical analysis also indicates that prototaxites gained their energy from diverse sources--ruling out the idea that they were plants.

This leads to the conclusion that prototaxites were giant, spire-like mushrooms--and the researchers who completed the analysis suggested that their height helped them to spread spores in an otherwise low-laying landscape.

An alternative explanation--perhaps attempting to account for the prototaxites' unusual height--suggests that they were a matted mixture of liverworts, fungus, and cyanobacteria that got rolled up by external forces and never stood upright. This has been disputed based on the fossils' anatomy and chemical makeup.

Tall, grey spires with no branches tower over the low plants of a landscape. Fog lays over the valley in the background with a mountain range in the distance.
A bearded man with a pick sits at the end of a long, grey prototaxite fossil in a bed of lighter, beige rocks.
Side-by-side images disputing the rolled liverwort theory. A diagram on the left shows that rhizomes would be oriented along the length of the prototaxite. An image on the left shows the perpendicular orientation of preserved rhizomes in prototaxite fossils.
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haq

Happy Black Country Pride Day to all the lovely Yam Yams out there!

I was reading a geology website, about Wren’s Nest, and my favourite bit was the image where they’ve labelled the location of Dudley 427,000,000 years ago with a big arrow, lol. Priorities!

A carefully labelled geological diagram with arrows pointing to important features, such as the Iapetus ocean crust, the Avalonian and Laurentian plates, the rough location of rocks that became England's south-eastern coast, and the biggest arrow pointing to the future location of the town of Dudley... in a nondescript patch of sea.
#geology#Dudley#Silurian
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Paleo Priest 🇪🇺🏳️‍🌈

Silurian acanthodian scale. Possibly Nostolepis gracilis taxa. From Silurian, Pridoli, Lithuania (EU). Preparing for my Master's 2nd semester work presentation. Sadly I have found almost no acanthodian fossils (yet), so I could not go and take better pictures (with SEM).Hope to gather at least 20 scales before going there.
#Silurian #Pridoli #fossil #fossils #micofossil #microfossils #paleo #paleontology #sketch #identification #acanthod

Extinct fish scale through microscope
Extinct fish scale through microscope
Extinct fish scale sketch
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haq

My favourite fossils aren't records of the dead, they're fossils showing the processes of being alive. The graded spacing of the ribs on the whorl of this 430 million year old fossil snail shell show periods of faster and slower spiralling growth. Poleumita funatis, about 2x2cm. Some fossils show regrowth after damage from accidents, disease, or attempted predation. /life finds a way

A photo of a grey-brown spiralling snail shell fossil with detailed rib patterns showing enough depth to be felt through fingertips.
#30DaysWild#FossilFriday#fossils
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