I’d bet on that being some kind of early ray; there could be a lot of tissue that wasn’t fossilized when the bone was.
Cringe but free
Could be! Still really cool (and weird) to see so much of the cartilage so cleanly preserved.
Echoing hymn of my fellow passerine | Art blog (under construction)
Apparently it is a lamniform shark. Rays were already modern in shape by the cretaceous IIRC.
The Hammerhead of it's day?
Those don't go as far back as the cretaceous, but, seeing tiger sharks are more closely related to hammerheads than to any other living species (and it shows a bit in the shape of their heads), and those were already around in the cretaceous, it is likely protohammerheads were doing their thing already.
This doesn't seem to have modern analogue. Well, weird lamniforms are still a thing, between megamouths, threshers, makos/porbeagles/G Ws and goblins.
I meant functionally, as in a feature that allowed it to move it's head sideways fast enough to catch certain types of fish.
The paper mentions it is a filter-feeder tho. So, more of a manta ray of its day.
Edited by Eriorguez on Mar 25th 2021 at 12:57:00 PM
Professional Writer & Amateur Scholar
I just learned that in a strict botanical sense strawberries are not actually berries.
...My life has been a lie!!
I'm a (socialist) professional writer serializing a WWII alternate history webnovel.
Oh, bother.
What, the fact the "seeds" are on the outside didn't clue you in already?
Another fun fact - bananas are technically berries. As are pumpkins and cucumbers.
BTW, raspberries aren't technically berries either. Nor are blackberries.
On a side note, cashews and walnuts aren't actually nuts either.
Edited by M84 on Mar 31st 2021 at 2:55:02 AM
Disgusted, but not surprised
Professional Writer & Amateur Scholar
My botanical knowledge is so non-existent that it didn't even register to me as a clue so, Imma say no.
I'm a (socialist) professional writer serializing a WWII alternate history webnovel.
Oh, bother.
Oh, and the reason I put seeds in quotes is because those aren't actually seeds either. Those are the actual fruits of the strawberry plant.
Disgusted, but not surprised
Yeah, neither strawberries nor pineapples are single fruits; strawberries are a fleshy inflorescence, so to speak, with their fruits being thin-fleshed and looking like mere seeds. Pineapples, well, every scale is a fruit; you can actually dislodge them from a ripen one and eat the comfortable portions.
Tomatoes are one of the best examples of botanical berry there are. And blackberries and raspberries are the same kind of botanical fruit as peaches and cherries, only in multiples; each "ball" in a black/raspberry has its own pit after all.
I’m reading a text on African history (The Civilizations of Africa: A History to 1800), and its provides a completely new perspective on the history of agriculture that’s fascinating. The text is a central resource on African history - there seem to be very few other good text books on the subject.
Basically, we start with a culture called the Afrasan, in the eastern Sudan-Eritrea area near the Red Sea. During the period 16,000-11,000 BC, still pre-agricultural, they started to harvest wild grasses for food. This began with harvesting tubers from a type of sedge and grinding the tubers to make flour. After a few millennia it shifted to include harvesting the seeds of other wild grasses, including threshing, winnowing, and grinding the grains to make flour and bake flatbread (as well as roasting the grains whole).
I would never have imagined that the invention of bread predated the invention of agriculture!
Anyway, harvesting grasses massively increased the amount of food they had available to them, so their population grew and expanded. Some of their descendents migrated into the Mideast and were the origin of the Semitic lamguage family there - and brought the practice of harvesting wild grains with them.
So when cultures developed agriculture, it was a fairly direct shift to deliberately cultivating the same plants they were already harvesting. Wild grain harvesters in Africa (Nilo-Saharan people who moved northward and picked up wild grain collecting from the Afrasans during a wet period around 9000 - 6000 BC when the Sahara became grassland) became wild grain farmers (sorghum and millet). Likewise, Mideast people who were at least familiar with wild grain harvesting from the Afrasans also started farming around the same time (wheat and barley).
For Niger-Congo people in West Africa, the wet period meant the rainforest expanded, making it harder for the yams that were their staple food to grow, so they shifted from harvesting the wild yams to deliberately cultivating them. Similarly, during a later period when things briefly got drier, another Nilo-Saharan hunter-gatherer group who relied on fishing saw their usual food sources dry up, and adopted the grain-farming practice from their neighbours.
It seems obvious now, that agriculture would start with people intentionally planting and fostering the growth of things they were already eating, in response to new resource constraints. Understanding the origins of grain farming in a hunter-gatherer society who already harvested wild grains - along with other people like the Niger-Congo culture also cultivating the things that had already been their main food sources - really makes all the pieces fit together a lot more clearly.
(No idea if rice farming in eastern Asia has similar origins.)
Edited by Galadriel on Apr 2nd 2021 at 11:58:53 AM
Redmess
I assume wild rice would grow in shallow natural ponds, so it might have started there.
Optimism is a duty.
![[up]](https://static.tvtropes.org/pmwiki/pub/smiles/arrow_up.png "[up]"){kind=icon}
Strictly speaking rice cultivation does not require the field to be flooded. It's just often done so because rice is more resistant to inundation than any weeds that might share the field so they are killed preferentially. There are forms of dry rice cultiavation that probably came first and wet farming developed once people were settled and the infrastructure for large scale irrigation was developed.
A procrastination in of itself
I could easily imagine it developing after an area flooded via storms and someone noticed that their rice field was actually doing better after being flooded than before.
“And the Bunny nails it!” ~ Gabrael “If the UN can get through a day without everyone strangling everyone else so can we.” ~ Cyran
Jared Diamond spends several chapters on that topic in "Guns, Germs and Steel", although he focuses more on the Fertile Crescent than on Africa.
Yes, Africa’s generally ignored in a lot of the history books, which is why I found it so interesting that grain cultivation in both Africa and the Fertile Crescent had its origins in African wild-grain harvesting.
Edited by Galadriel on Apr 3rd 2021 at 9:36:19 AM
Our species originates in Africa. There is more genetic diversity in sub-Saharan Africa than in the entire rest of the world. Buuuut...
Are you sure that's the consensus? Because I'm pretty sure people collected wild grains elsewhere.
There are so few people who have seriously researched Africa that it’s hard to know what a broader perspective would say, or if that beoader perspective would be correct. The text says wild grain gathering originated first in Africa, and the linguistic evidence shows migration of that same grain-collecting people group into the Mideast quite early on, so it seems like a reasonable conclusion to draw.
It seems like, in general in prehistory, when a new technology or practice emerges somewhere, and then there’s a documented move of those people into a second region, and then that practice shows up in the second region, that it spread from one to another rather than originating independently. So the author’s conclusions seem in line with good historical practice to me, and the reviews I have found of the book by other academics are very positive. But he’s definitely challenging a lot of established assumptions in certain respects; I don’t know if this is one of them.
Edited by Galadriel on Apr 3rd 2021 at 10:48:22 AM
The reason I ask is because from other sources
I understood that wild grain collection appeared first in the fertile crescent, and expanded from there. The dates you mention are earlier than that, however. Do you have a reference for the text you are using?
The Civilizations of Africa: a history to 1800, by Christopher Ehret (published 2002; there’s also a more recent 2nd edition). The book says start of wild grass collection in the areas of northeast Africa west of the Red Sea was the harvesting of tubers from certain kinds of sedges and griding them into flour around 16,000 BC, and this progressed to harvesting of seeds from wild grasses in 13,000-11,000 BC (15,000-13,000 years ago).
The book specifically mentions the Natufian culture of the Middle East, who are the wild grain collectors mentioned in the Encyclopedia Brittanica entry you linked, and outlines their outgrowth from the African practice of wild grain collection:
By the 12th millennium [11,000s] BCE at the latest, wild grass and grain collecting had taken hold as far north as northern Egypt. One offshoot of this cultural complex, the Mushabian culture, then spread across the Sinai Peninsula from Africa into Palestine and Syria. There the Mushabian communities established themselves as neighbours of peoples belonging to the Geometric Kebaran culture, already long present in Palestine and Syria. Out of the interactions between these two cultures a new mixed culture, the Natufian, strongly committed to the practices of wild grain collection, then emerged between 11,000 and 10,000 BCE.
The Brittanica article on the Natufians specifically dates them to around the 9,000s BC, which roughly lines up with this chronology.
And in another section:
...The idea of collecting wild grains did not spread from Africa into Palestine, Syria, and the fringes of Turkey and Iran until about the 11th millennium [10,000s] BCE. Only after that idea took hold there did it become possible for the inhabitants of those Southwest Asian regions to take the further step of domesticating their own suitable wild grains, wheat and barley. This they did 1,000 years later, in about the 10th and 9th millennia [9000s and 8000s BCE].
It also says that some of the historical interpretations (it doesn’t mention if this is one of them) rest on recent findings and there is not a consensus about them. But in general encylopedias are a fairly conservative source and slow to incorporate new findings that are still under scholarly discussion. Notably, there are at least 3 different early agricultural traditions in Africa, going by the textbook, and the Brittanica article doesn’t mention any of them.
Edited by Galadriel on Apr 4th 2021 at 6:19:18 AM
But Diamond does, and specifically mentions food production emigrating from Southwest Asia to Africa (Ethiopia first, then West Africa). Of course, he's talking about plant domestication, and while he discusses wild plant collection he doesn't date any of it, so both theories are broadly consistent. It would imply a two-way exchange of innovations: plant collection from East Africa to the Fertile Crescent, and then plant domestication back from the Fertile Crescent to Africa. Fascinating if true.
Both sources are rather dated by now, so it would be nice to have a more recent summary of the evidence.
Edited by DeMarquis on Apr 4th 2021 at 9:17:52 AM
It's Shark Sunday! Time to see the new shark, just dropped — OH MY GOD WHAT THE FUCK
Fossil of 'long-winged' shark from Cretaceous period found in Mexican quarry.
The shark, dubbed Aquilolamna milarcae, was 1.7 metres long but boasted a fin span of around 1.9m.
It cruised the oceans, fins out to the side like a glider, sifting plankton from seawater that flowed through its gaping mouth.
In a paper published in the journal Science
today, a team of palaeontologists said Aquilolamna sharks lived from about 93 million years ago until they died out during a mass extinction 66 million years ago.
The fossil illustrates the first time a body plan with super long pectoral fins has been found in sharks, according to Romain Vullo, a palaeontologist at the University of Rennes in France and lead author of the paper.
"If you replace its pectoral fins with normal fins, it would look like a normal shark," Dr Vullo said.
"The thing very strange [about the fossil] is its pectoral fins, which really are extraordinary."
While the long pectoral fins on either side of Aquilolamna's body are reminiscent of the wide, flappy fins on manta rays, the animals are not related.
Rays evolved well after the extinction event that wiped out three-quarters of the world's plant and animal species.
During that event, intense climate change caused oceans to acidify, which ate away at the calcium carbonate skeletons and shells of some plankton species.
As plankton died off, so too did the animals that fed on them — like Aquilolamna.
Plankton eventually rebounded. And without Aquilolamna roaming the oceans, manta rays and other plankton-eaters were free to evolve around 30 million years later, Dr Vullo said.
Flinders University palaeontologist John Long said the discovery shows the "awesome plasticity" of evolution.
"[Body] forms can adapt to whatever food sources are out there that might be in abundance," said Professor Long, who was not involved in the study.
"Life shapes itself according to nature's cafes."
A fishy find, south of the border
The fossil was discovered in a limestone slab in northern Mexico, not too far from the US border.
Back in the late Cretaceous period, from 66 million to 100 million years ago, that area was submerged by an ocean.
By then, fish species with a skeleton made of cartilage, such as sharks, had been around for a while. They first appeared about 380 million years ago.
But cartilage, despite being strong and flexible, isn't as hard as bone or teeth. This means it's less likely to fossilise.
"So you need to have very special conditions to preserve cartilaginous fishes because their skeleton is not mineralised like bony animals," Dr Vullo said.
"We think when this individual died, its body sank to the bottom [of the ocean].
"It was rather deep — probably between 200 and 300 metres — and the bottom was soft and muddy."
The body, which flew under the radar of scavengers, was covered in sediment.
As the aeons passed, that mushy sediment turned to limestone and that patch of seabed was thrust out of the water.
In 2012, a quarry worker split that rock slab, and the ancient fish was once again brought to light.
Building a life story from a fossil
A single fossil can tell palaeontologists plenty about where the animal lived, what it ate and how it behaved.
The shape of Aquilolamna's tail is typical of sharks that don't rely on speed to eat.
Its blunt head with a wide mouth sitting at the front looks a lot like plankton-eating filter-feeding sharks that cruise oceans today.
And its long pectoral fins were perfect for navigating the open ocean.
Unlike rays, which flap their wings to move through the water, Aquilolamna mainly used its pectoral fins as stabilisers, and used its tail to propel itself, Dr Vullo said.
The long pectoral fins seen on the ancient Aquilolamna and present-day manta rays are a great example of convergent evolution, said Will White, an ichthyologist at CSIRO.
"The pectoral fins are such a unique structure. No other animal has something like that. And they're completely different groups — they have not evolved from each other.
"But in two different points in the evolutionary history, these organisms have basically evolved this specialised feature completely independent of each other."
Of modern-day sharks, the enigmatic megamouth shark (Megachasma pelagios) has fairly long pectoral fins, Dr White added, but they're nowhere near as big as Aquilolamna's.
Toothy problem
The fossil skeleton is almost complete, but crucially, is missing its teeth.
Dr Vullo suspects they were dislodged after the animal died and lost during fossilisation.
It could be they're buried a couple of millimetres in the limestone, but the slab is too big to scan and find out.
Teeth are important in identifying sharks. Most extinct shark species are known by their teeth alone.
That's because unlike their relatively soft skeleton, those hard, mineralised teeth fossilise easily — plus there's more of them.
Sharks continually grow and replace old teeth. Some species go through up to 20,000 teeth over their lifetime.
Yet Dr Vullo and his team suspect teeth belonging to the same family of long-finned sharks may have already been discovered.
In 1990, a trio of palaeontologists unveiled teeth belonging to a group of fish called Cretomanta.
They lived at the same time as Aquilolamna, and their teeth were found in Texas — not too far from Aquilolamna's discovery site.
And once the pandemic allows, Dr Vullo plans to look for Aquilolamna teeth, through existing fossils and by revisiting the site in Mexico.