Category: Iotd

Living fossils

Living fossils can be found and recognised over long periods of geological time, and appear very similar throughout. And they may have little diversity, in other words the species in the group all tend to be similar to one another.

Leaves of Ginkgo biloba, the Maidenhair tree

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Image of the day – 172

Every now and again biologists discover a plant or animal that looks uncannily like a known fossil. It’s happened a number of times.

Ginkgo leaves Wikimedia

Living fossils have two main characteristics, although some have a third:

  1. Living organisms that are members of a taxon that has remained recognizable in the fossil record over an unusually long time span.
  2. They show little morphological divergence, whether from early members of the lineage, or among extant species.
  3. They tend to have little taxonomic diversity.[5]

The first two are required for recognition as a living fossil; some authors also require the third, others merely note it as a frequent trait.

To put this more simply, Living fossils can be found and recognised over long periods of geological time, and appear very similar throughout. And they may have little diversity, in other words the species in the group all tend to be similar to one another.

Here are some examples, listed in order of their discovery. In some cases the fossil organism was already known before a living form was discovered, in other cases the living form was known first:

  • Dinoflagellates (1753, worldwide in salt and fresh water)
  • Ginkgo or ‘Maidenhair tree’ (1800s or before, southwestern China)
  • Echinothurioida or ‘Soft sea urchins’ (1870s, southern England)
  • Eomeropidae or ‘Scorpion flies’ (1909, southern Chile)
  • Coelacanth there are two living species (discovered in 1938 in the Indian Ocean) and (late 1990s off Indonesia).
  • Metasequioa ( discovered in 1941 in Hunan, China)
  • Glypheoid lobsters (1970s, Philippines)
  • Jurodidae or ‘Jurodid beetles’ (1996, Siberia)
  • Mymarommatidae or ‘false fairy wasps’ (2007ish, North America)
  • Syntexis libocedrii or ‘cedar wood wasp’ (2011, California to British Columbia)

What else can we learn from this

Two things really. The first thing is that species can sometimes exist for very much longer than normal. And the second thing we learn is that species with astonishingly similar appearance may rise independently more than once. So-called fossil species may be no more than independently arising lines that happen to look very similar.We see the same thing between different living groups, so there’s a marsupial mouse that looks quite like its European namesake. This is known as parallel or convergent evolution.

See also:

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Crystalline inclusions in Cotswold stone

It seems that quartz geodes are not unusual in Oolitic limestone deposits.

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Image of the day – 171

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

Click to enlarge

There’s a long stretch of dry stone Cotswold wall along the western edge of the Gloucester Road between Cirencester and Stratton. Walking along the footpath one day I was surprised to see the crystalline inclusions featured in this photo. The crystals look to me like a form of quartz (six-sided columns with six-faced prisms at both ends).

This might be part of a geode fractured open while quarrying the stone. There’s a small chance that the other side of the geode exists elsewhere in the same wall or in some other structure built around the same time. It seems that quartz geodes are not unusual in Oolitic limestone deposits. When they are stained purple purple the crystals are known as amethyst. The formation in the photo shows no hint of colour at all. The deposit must have formed from a particularly pure solution of quartz.

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A canal walk through Chalford
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A grand old house in Cirencester

Mullings engaged the architect William Jay to design the house, and Watermoor House was accordingly built around 1827 in the Greek Revival style

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Image of the day – 170

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

Click to enlarge

The land now occupied by Watermoor House and St Michael’s Park may once have been common land. But early large scale Ordnance Survey maps mark a much larger area, including that now occupied by the house and park, as a large nursery. It might have been owned at one time by Richard Gregory who was a Cirencester nurseryman in the 1790s.

The business (and probably the land) passed into the hands of John Jefferies at least by the early 1800s, and it seems that Randolph Mullings, a local solicitor, bought a substantial piece of it in order to build a large house in its own grounds. The details remain unknown, but Gregory, Jefferies and Mullings were known to one another, and Jefferies worked as a manager for Gregory on the nurseries. Gregory lost much of his money by providing surety for a friend’s loan, and Mullings advised Jefferies to continue managing the business and wait to see how things would work out.

Having acquired part of the land, Mullings engaged the architect William Jay to design the building; Watermoor House was constructed to Jay’s plan around 1827 in the Greek Revival style; and the garden and park were added to complete the property. The house is now grade II listed.

At some point Watermoor House became a private school until it closed in the 1950s or 60s. It may have had some other function following this, but today it is a residential care home.

I’ve cobbled this tale together from limited sources that may or may not be reliable. There are also many gaps. It would be good if the story could be properly researched by someone with the time and skills to undertake it.

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Resources for Cirencester history

What do we see here?

The water flows in the town are complex, this section is often known as Gumstool Brook, but it might also be regarded as a diverted part of the Churn.

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Image of the day – 169

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

Click to enlarge

At the top of the image you can see the rears of buildings on Cecily Hill in Cirencester. Their gardens contain the trunks and foliage of mature trees just beyond the wall. The wall separates those gardens from the water channel and may have been built specifically for that purpose. Some of the tree branches have grown across the top of the wall.

Near the base of the wall is a distinct line, brown below and much paler above. I think the brown part of the wall is often underwater. The water flow is strongly seasonal, high in wintertime and much, much lower in the summer. The River Churn divides at the Gloucester Road bridge, only a kilometre from this point. The major branch follows the outside of the Roman city wall and usually continues to flow all year round. But the branch in the photo is fed from the outflow of the long, narrow, supply pound for Barton Mill and this in turn is fed from the main flow of the River Churn. The water flows in the town are complex, this section is often known as Gumstool Brook, but it might also be regarded as a diverted part of the Churn.

The pipework at the bottom of this wall was there in the 1950s and 60s when I was a child. Most of it was hidden then by a low wall topped with flagstones, but today much of the structure has fallen away exposing the glazed pipes. Out of the photo a little further to the left, the water disappears underground, running south of Coxwell Street and reappearing at the surface further west in the Abbey Grounds.

It’s good to know that the Town Council and the Friends of Gumstool Brook are looking into ways of improving the flow of this watercourse by adjusting the sluice management rules. We might see the water flowing properly all summer in 2026.

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If you enjoyed this or found it useful, please like, comment, and share below. (If you don’t see those links, click the article’s title above the main photo and they will appear.) Send a link to friends who might enjoy the article or benefit from it – Thanks! My material is free to reuse (see conditions), but a coffee is always welcome and encourages me to write more often!

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Image of the day – 72
Churn flood plain
Churn flooding

Caring on the water

It might be as simple as a kind word at the right moment, or a helping hand to steady someone losing their balance, or even just a smile.

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Image of the day – 168

What’s in an image? Sometimes quite a lot, more than meets the eye. I’m posting an image every few days.

Click to enlarge

This boat, seen here on the Gloucester and Sharpness Canal, is based at Saul Junction in Frampton on Severn. It might look like a tourist boat available for hire by the public, but it serves a different and entirely charitable purpose. Two similar (but not identical) special boats were built to provide opportunities for disabled or seriously ill people to experience a day on the canal for free. And for those that want to, they are also given the chance to explore the boat, see how it all works, hold the steering gear and so forth. The boats are designed for wheelchair access too. Check the See also link below for details and photos from the Willow Trust website.

I love to see examples of effort and resources being expended by enthusastic teams to greatly benefit those who need and deserve help. Every one of us can see the need for support of this sort, though not all are able or willing to provide it. But every single person in the world can do something positive to help others one way or another. It might be as simple as a kind word at the right moment, or a helping hand to steady someone losing their balance, or even just a smile. All it takes is an open eye, an attentive ear, and a willing mind.

If you are a wealthy person you might give thousands of pounds towards maintenance and fuel costs for these boats; if you have some spare time but no money, you might give time and energy to help with tidying and cleaning a boat between trips or helping in other practical ways. No matter what we do or do not possess, there’s always something we can offer.

It’s about contributing something, anything, in a world that’s not always fair or kind. And there are so many considerate, helpful organisations out there – everyone can find worthy opportunities in every town and most villages around the globe; even where there’s no local group or organisation, there will be many local opportunities to find and fill a need of some kind.

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Useful? Interesting?

If you enjoyed this or found it useful, please like, comment, and share below. (If you don’t see those links, click the article’s title above the main photo and they will appear.) Send a link to friends who might enjoy the article or benefit from it – Thanks! My material is free to reuse (see conditions), but a coffee is always welcome and encourages me to write more often!

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Footbridge in Bedford
The art of persuasion
Ingredients of kindness