Stratigraphy, Sedimentology and Palaeontology

Stratigraphy, Sedimentology and Palaeontology

Slimy Landscapes 2: This time it’s Precambrian

Slimy Landscapes 2: This time it’s Precambrian

Slime is important to the developments of Earth’s landscapes – I have already explored this in a previous post where I learnt how Extracellular Polymeric Substances (EPS), a fancy phrase for a slime produced by organisms, can bind sediments together and making them resistant to erosion. This has impacts on the development of landscapes, from the types of bedforms forming below flows, the rate at which cliffs erode, and the shape deltas take. However, it seems this is just the beginning and the more you dig the greater the influence this slime has had on the planet and its inhabitants.

Let’s go back to the deep ocean, 635 million years ago, where the waters are well oxygenated and full of simple plants and animals. Fast-forward over a hundred million years, beginning 540 million years ago, and there is a sudden explosion in the evolution of life, with ecosystems similar to the present day emerging and the lifeforms becoming my complex. We have travelled from the Ediacaran to the Cambrian and the world has been turned upside down.

I spoke to a couple of researchers at the Energy and Environment Institute, University of Hull, who are researching this sudden change. They work on a project called Worms on Film and both are using art as a way of communicating their research. Catherine Mascord explained to me –

“Before this transition, with nothing to disturb them Precambrian seafloors, including those of the Ediacaran, are generally characterised by prevalent anoxia and sulphur rich sediments. Without animals to break up and disturb the sediment most of the seafloor was blanketed in a thick community of microbes, known as a microbial matground, formed when bacteria and other microorganisms glue themselves and their host sediment together through the secretion of EPS.”

A talented scientist and artist, Catherine uses her talents to communicate her research. This diagram shows the difference between the surface/sub-surface eco-systems of the Ediacaran and the Cambrian.

It was the evolution of burrowing animals, like worms, that initiated the transition from the Ediacaran to the Cambrian, and Catherine’s research is helping us understand this better through a mix of field work and experiments using modern worms.

“We can use modern animals with similar burrowing behaviours as models for ancient animals and use then to help figure out how an animal behaves in Ediacaran-like conditions.”

These worm-like burrowers were key to breaking through the 2-dimensional habitat that was being reinforced by EPS. The sub-surface was barren, de-oxygenated, and lifeless. The emergence of the burrowers broke through this crust and enabled the sub-surface to be oxygenated. I spoke to Jenny James, who is researching the links between climate change and mass-extinctions as part of Worms on Film.

“Marine worms are eco-system engineers; they increase oxygen penetration depth into the sediment allowing microbiota to survive at a greater depth and speeding up the process of nutrient cycling; they also stabilise the sediment by secreting a mucus-like substance (EPS) to line their burrows.”

Although the burrows made by the worms are reinforced, they are not invincible and changes to the planet’s climate can impact on the eco-systems they create. Moving forward in time again to the end of the Permian (252 million years ago) and once again the ocean floor is a barren, 2-dimensional landscape. Rising atmospheric Carbon Dioxide levels at that time caused an acidification of the oceans.

“The knock-on effects on marine ecosystems can often be seen in the fossil record as a rapid decline in biodiversity and even a loss of trace fossils such as burrows and surface trails. The End Permian mass extinction saw a prolonged gap in burrowing animals such as worms and bivalves and because of this, the 3-dimensional benthic habitat became barren and 2-dimensional.”

Also a talented scientist and artist, Jenny sculpted this steampunk representation of a Harbour Ragworm and the Carbon Dioxide so influential to its eco-system.

Jenny is using a particularly resilient species of worm, the Habour Ragworm, to identify whether these patterns seen in the geological record could be repeated due to anthropogenic climate change.

“Similar patterns are beginning to occur today with rapidly declining populations of most vulnerable marine animals such as corals.”

Once again, I am amazed at the impact that small animals, microorganisms, and the mucus they secrete have had in shaping the planet we see today. It seems from the research Catherine and Jenny have showed me, and the results they will produce in the future, that these creatures are not finished shaping our landscapes just yet.

EPS will return in Slimy Landscapes 3.*

*suggestions for titles welcome!

DeepDust ICDP workshop in Norman, Oklahoma, USA discussed drilling the equatorial terrestrial Permian

From microbiology to geophysics – more than 50 international participants of the first DeepDust Workshop covered a wide range of topics. In Oklahoma researchers exchanged views on a possible international drilling project to study the continental geology of the Permian. During a change from the cold to a warm period, large ice masses melted. This may provide interesting insights into current and future climate developments.

After arriving from all around the globe and sharing a joyful ice breaker, the DeepDust workshop started with an introduction to the International Continental Drilling Program (ICDP) including its setup and possible support for projects. This was followed by an introduction to the Permian, highlighting the interest in Permian equatorial terrestrial geoarchives which may partly serve as Mars analogs. The need for a better understanding of this time period and setting was highlighted clearly. The first afternoon was spent with understanding the challenges of different possible drilling areas.

The second day was spent on an excursion where we saw Permian mudstones, including evaporites and siltstones in Oklahoma. The third day was mostly spent discussing key questions and how these may be answered. Discussions included practicalities such as obtaining site survey data and drill planning. The workshop ended with reviewing major objectives and how these may be achieved efficiently regarding, among others, drilling and funding.

Personally, I really enjoyed participating in such an international and focussed workshop. I learned a lot about the Permian, the Geology of Oklahoma and met many enthusiastic colleagues. I am looking forward to continuing pushing the DeepDust project forward.

The workshop participants in front of Permian mudstones in Oklahoma during the workshop field trip.

EGU goes greener, let’s go greener to EGU

For those in a rush, here is the conclusion already:
EGU is doing great efforts to become more environmentally friendly, but the huge issue of any conference lies in one aspect: participants flying there… Could we, participants, rush into the train next year?

I would not have realized all the evolutions of this year’s EGU2019 General Assembly if they had not been told to me. And that was precisely one of the goals of the evening session on “The carbon footprint of EGU’s General Assembly” led by Susanne Buiter, Jonathan Bamber, and Alberto Montanari (1). Since many of us couldn’t enjoy this in live, here is a summary in two acts: (i). What has been done, (ii) What could be made better.
I’ll conclude about air travel and groups that organize to limit it.

What has been done

A series of measures have been taken this year, some of them discrete or barely noticeable, but with a tremendous impact:

Carbon Offsetting programs:

For two years now, all participants are offered to offset their CO2 emissions related to the conference during the registration process. In 2018, support was given to a project to reduce deforestation in Brazil (2, 3). Donations allowed to support for about 4.251 tons of CO2. In 2019, participants could choose between 3 projects in Indonesia, Uganda, or Kenya. Whereas this is not the ultimate solution to make the General Assembly greener, it should be a mandatory transition for what cannot yet be perfected.

Printed Programme book:

The printed Programme book of 190 A5 pages was NOT distributed to the 15.000 attendees anymore. Instead, everything was available from the app and on the website. In case you felt a slight discomfort about it, I’m sure you’ll be happy to realize how many pages that makes, together with 15,000 metal spiral bindings. Also since 2019, the daily newspaper “EGU Today” went all online, saving around 15,000 double-sided A4 printed pages.
Actually, if you are a long-time regular attendee, you may have noticed that the full printed Programme book of 800 A4 pages stopped already back in 2007, whereas the initiative of distributing the Programme on USB sticks ceased after 2011.


This year, the floor of Hall A (a surface of 2.890 sqm) was kept free of single-use carpets.
– if you missed it, here is a post about single-use carpets from our blog: “EGU’s lost strata” (4).-
This is a great reduction of ca. 15%, but keep reading to know about what could happen to the remaining 17.230 sqm! Currently, the single-use carpet is down-cycled for noise-absorbent mats for cars and house building. The reason that the poster halls need carpet is for reducing the high noise levels. EGU is investigating options to reduce the noise in a more environmental friendly manner.

Water packaging:

Those 30.000 water PET bottles distributed in 2017 were replaced by water fountains in 2018, when we all received refill-bottles during registration. This year’s idea was even easier and effective: bring your own bottle to refill at the fountains.

Vegetarian lunch bags:

During the division meetings and lunchtime events, all meals were vegetarian. Yes, eating vegetarian is good at least for the climate (without entering into the subject of the benefits for your own health, the well-being of animals, or the fascinating book from Peter Singer revisiting our ethical bases (5) in 1975). I am very convinced that most attendees did not miss the ham sandwiches, and that even meat-lovers were happy to taste the vegetarian falafel option. Yes, even a meat-eater can enjoy a vegetarian meal. More about vegan lunch comes below.

Train discount:

-Since 2018, a reduction on the train ticket was put in place to attend EGU-Vienna by train departing from Switzerland (a 25 CHF discount for a return ticket). This initiative was rated as very successful by the Swiss train company (SBB) based on the response rates, an excellent result that might convince other companies around Europe to join. The extension of a similar scheme to some other national railway companies has unfortunately not been successful yet. The idea of reserving special EGU trains has also been investigated but seems fairly complicated due to administrative regulations, the need to reserve a track path 2 to 5 years in advance, and would require a substantial safety deposit.

Returning beer bottles:

-About 40.000 beers were served in returnable glass bottles this year. It only depends on us to return these empty beers to the collecting boxes that can be found everywhere in and around the building.

What could be made better

In the forthcoming years, several other changes might come up to improve our environmental impact and use of consumables:

Reusable carpet:

That’s my favorite! Where possible, single-use carpet was already removed this year. However, our poster Halls in the basement are installed in an underground parking, so some noise reduction and embellishment are needed. What if the carpet was not thrown away at the end of the week but re-used? I’d love to pay the small extra cost that it would induce (7.32 Eur per attendee).

Coffee cups:

A provision of 108,000 paper cups was prepared for the 2019 General Assembly. We the attendees could actually bring our own coffee mugs! I personally had not even thought about it until other participants suggested it to me (although EGU had a #EGUmug competition on twitter to raise awareness). A nice gesture from all of us next year?


I want to ride my bicycle I want to ride it where I like“. Queen’s wish from 1978 should become real in 2020 at EGU: We should get a facilitated access to “City Bike Vienna” (6) and bike parking sites at the conference center.

Vegan lunch bags:

A choice of vegan lunch bags at lunch-time events could be provided. It is hard to guess how many attendees are vegan because of the huge span in numbers between countries and studies, together with a bias that veganism is more of an affluent (elitist) phenomenon (7)… Independently of this, a vegan food option could comply with the diet needs for a few hundreds of attendees, it might well lower the carbon impact of EGU, and it is enjoyable even without following a vegan diet.

Streaming and videoconferencing:

Currently EGU webstreams union-wide sessions, such as the Union Symposia and Union medal lectures. A possible future for EGU would be to webstream more sessions and even allow speakers to give their talk remotely as a videoconference. Saving a flight from Sydney to Vienna would spare 2.37 tons CO2… (8). Remote attendance may need a registration fee to cover the costs of webstreaming and rental of the conference centre. This might also be attractive to the very busy geoscientists or those having teaching duties during the General Assembly. Of course, an important reason for attending conferences is meeting colleagues and networking. That, unfortunately requires travel, and here is where we as participants have a responsibility.

Green meeting certification:

The Austria Center Vienna (ACV) hosting the General Assembly offers support and provide free green meeting certification in compliance with the Austrian ecolabel (9). A short term goal for EGU could be to achieve the mandatory criteria to be met in nine areas and become certified as a green meeting.

Condemn air travel

The EGU and Copernicus teams are doing large efforts to go greener. This is great, but let’s admit it: the one huge CO2 weak spot of a conference lies in the travel impact of its attendees. Flying is “the most carbon-profligate activity (per hour) humankind has thus far developed”… This is why EGU is trying hard to encourage the use of train (see above). But do we actually need any support to take the train? No, this is a self-motivated, moral choice, and several groups of scientists have already organized to condemn air travel by researchers:

-A petition currently received >1800 signatures for their “Call on Universities and Professional Associations to Greatly Reduce Flying” (10) with >600 of the signatories being researchers. The petition is anchored to a blog providing information and resources around the issue (11). Please sign and spread it as well!
-The “No fly climate Sci” was created by Earth Scientists and groups around 290 biographies of academics and non-academics that decided to reduce their travel by plane (12).
-In France, the recently created group “Labos 1.5” promotes clean practices in Science (13). They published their seminal text in the newspaper “Le Monde” (12), the latter also publishing other tribunes about scientists’ addiction to kerosene (13).
-As a member of the University of Bern (CH), I acknowledge to be in a very privileged situation. It is a huge pride that the majority of our lab took the 10 hours train ride to attend the General Assembly (>20 persons). The University of Bern dissuades air travels; our travel reimbursement forms state that “Flying has to be limited to the unavoidable and CO2 emissions have to be compensated* (14)”. If you are part of a lab that similarly fosters environmentally friendly practices, please share your experience in the comments!

These examples of initiatives show us one fact: things are moving, less and less scientists accept to plead the importance of their work to destroy the environment. We feel the “flygskam” (15). It’s time to change our practices. And in case this text is troubling you, it is probably not going to be the last one: the flood of millions of high-school students supporting Greta Thunberg is about to join the ranks of our universities.


*In German: “Flugreisen sind auf das Notwendigste zu beschränken. CO2-Emissionen sind grundsätzlich mittels eines Klimatickets zu kompensieren, dessen Wahl in der Kompetenz der Organisationseinheit liegt. Die Kompensation ist über Drittmittel zu finanzieren.

Paleontology is sexy! A selection of recent discoveries

The 2019 started with a relatively high number of paleontological discoveries published in highly ranked journals showing that paleontology is sexy indeed! Here you can find a small selection of the most recent ones. The studies in micro- and macropaleontology published earlier this year, provide a large contribution to our understanding of organism evolution and response to peculiar environmental conditions which can be used to predict future ecosystem reactions. Paleontology is therefore not only fascinating but it is a valid instrument for assemble a possible scenario of biotic changes in the future.


A gigantic carnivore from the earliest Miocene of Kenya

A relatively young adult of a gigantic carnivore from the early Miocene (ca. 22 million years ago) was discovered at Meswa Bridge, Kenya. The researchers, Borth M. and Stevens N., called the now extinct carnivore Simbakubwa kutokaafrika, Swahili for “big lion from Africa” since this predator would have played a lion-like role. It is the oldest known member in a group of extinct mammals called hyaenodonts, so named due to their dental resemblance to hyenas, even though the groups are also unrelated. The specimen was known from most of its jaw, portions of its skull and parts of its skeleton. It was larger than a modern polar bear, it weighed up to 1,500 kilograms, measured 2.4 meters long from snout to rump and stood 1.2 m tall at its shoulders.The study was published in the Journal of Vertebrate Paleontology  and helps connect some of the evolutionary steps for this group which were near the top of the food chain in theAfrican ecosystems where early apes and monkeys were also evolving. The fossil may also help scientists better understand why these apex predators ultimately did not survive.


A modern lion skull (above) compared to the left part of a Simbakubwa kutokaafrika jaw (below) photographed by Matthew Borths. On the right, a rendering of Simbakubwa kutokaafrika (image credits Mauricio Anton).



Exceptional preservation of mid-Cretaceous marine arthropods and the evolution of novel forms via heterochrony

A new, exceptionally preserved crab from the mid-Cretaceous of Colombia and the United States was discovered by Luque et al. The completeness of the fossil remains shed light on the early disparity of the group and the origins of novel forms.This ancient crab was named Callichimaera perplexa, which means “perplexing beautiful chimera”, and lived during late Cretaceous (ca. 95 to 90 million years ago). The name references the mythical chimera from Greek mythology, which had a lion’s head, a goat’s body and a snake’s tail. The C. perplexa had large unprotected compound eyes, small fusiform body, and leg-like mouthparts suggesting larval trait retention into adulthood via heterochronic development (pedomorphosis), while its large oar-like legs represent the earliest known adaptations in crabs for active swimming. The authors, who published their study in Science Advances, think that these creatures lived in the water, swimming more than crawling  around on land (due to the unusual legs) and were active predators.


A rendering of Callichimaera perplexa (Image credits Oksana Vernygora / University of Alberta). On the right dorsal, frontal, and ocular features in Callichimaera perplexa, from the mid-Cretaceous of Colombia (Luque et al. 2019) .


Unlaid egg discovered in an Early Cretaceous bird fossil

A new enantiornithine, Avimaia schweitzerae gen. et sp. nov., from the Lower Cretaceous Xiagou Formation was described by Bailleul et al. The discovery is of great importance since it tetifys the oldest documented case of a common reproductive disorder: called “egg-binding,” where an egg becomes trapped inside a bird. The fossilized bird was in fact found with an unlaid egg two-dimensionally preserved within the abdominothoracic cavity. Ground-sections reveal abnormal eggshell proportions, and multiple eggshell layers best interpreted as a multi-layered egg resulting from prolonged oviductal retention. The find, reported in Nature Communications, belonged to a sparrow-size flyer that lived in northwestern China ca. 110 million years ago. The team has named the bird Avimaia schweitzerae (Avimaia means “mother bird”; and schweitzerae honors paleontologist Mary Schweitzer.)


A rendering of the female individual Avimaia schweitzerae dead in the water on the left (with an unlaid egg not visible inside its abdomen), represents the fossilized individual discovered in China. Illustration by Michael Rothman. In the center and right side, photograph and line drawing of the holotype of Avimaia schweitzerae, IVPP V25371. a Photograph of the partial skeleton with feather impressions, and the crushed preserved egg between the pubes; b interpretive line drawing, with white arrows indicating the two fragments extracted for microscopic analysis with a super-imposed CT-scan revealing the egg and underlying elements of the right pelvis in dorsal (synsacrum) and medial (ilium) view (from Bailleul et al. 2019).



A new African Titanosaurian Sauropod Dinosaur from the middle Cretaceous of Southwestern Tanzania

Paleontologists recently discovered a new titanosaurian sauropod – a giant, plant-eating dinosaur – and named it Mnyamawamtuka moyowamkia. A common component in Cretaceous African faunas, titanosaurian sauropods diversified into one of the most specious groups of dinosaurs worldwide and this discovery is helping paleontologists understanding how, where and when the mightiest of land animals evolved. Mnyamawamtuka moyowamkia lived around 100-110 million years ago, during the middle of the Cretaceous and was found in the Mtuka Member of the Galula Formation  (Aptian–Cenomanian) in southwest Tanzania.

Titanosaurs are best known from South America, Tanzania, Egypt, and other parts of the African continent. The new specimen described by Gorscak and O’Connor in PlosOne preserves teeth, elements from all regions of the postcranial axial skeleton, parts of both appendicular girdles, and portions of both limbs including a complete metatarsus. This finding adds a bit more detail to the picture of what ecosystems on continental Africa were like during the Cretaceous.


All these findings make you wonder: ‘what else is out there for us to discover?’