Codex of 15th and 16th Century Mexican Earthquakes (Tlalollin)

 

"The written chronology in a 16th century codex was created by a pre-Hispanic civilization.

 It is one of the oldest-known records of an earthquake which occurred in Mexico in 1507

(see below).

       The earthquake is represented by the symbol (to the middle, right) 

composed of four dotted yellow rectangles representing the layers of 

the earth) overlain by four helices (in blue and white) with a red eye 

at the center. The pictogram also describes one impact of the quake

--the drowning of 1,800 warriors in a river (bottom).

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          A 50-page codex of colorful, complex pictograms that dates to the early 16th century includes the most complete (and one of the oldest ) written chronologies of early earthquakes in the Americas.

      The Telleriano-Remensis, which was created by an unknown pre-Hispanic civilization, describes twelve separate earthquakes that shook in what is now Mexico and central America from 1460 to 1542 researchers report in the August 25, 2021 issue of Seismological Research Letters.       The famous codex was written by specialists called tlacuilos, meaning “those who write painting” in the Nahuatl language spoken byAztecs and other pre-Hispanic civilizations in the area (Science News, March 13, 2020).

      Using other codices from the region, researchers had previously identified the combination of two pictographs that denotes an earthquake. One shows four helices around a central circle or eye, and stands for ollin, meaning “movement” in Nahuatl. The other pictograph shows one or more rectangular layers filled with dots, and means tlalli, or “earth.” For daytime earthquakes, the eye is open; for nighttime quakes, it’s closed.

In codices written by pre-Hispanic civilizations who spoke Nahuatl, such as the Aztecs, the combination of two symbols represents an earthquake, or tlalollin. One pictograph (left) shows four helices with a central eye and stands for ollin, or “movement.” The second (right) is a rectangular box filled with dots, often in layers, and represents tlalli, or “earth.”

      Seismologist Gerardo Suárez of the National Autonomous University of Mexico and social anthropologist Virginia García-Acosta of the Center for Research and Higher Studies in Social Anthropology, both in Mexico City, pored over the Telleriano-Remensis. The researchers were looking for representations of quakes, comparing what they found to accounts of quakes in other pre-Hispanic codices and texts written later by Spanish friars.

     The Telleriano-Remensis uses a pictorial representation of a 52-year cycle to roughly date the quakes. Years are represented by these four signs:

tecpatl (knife), 

calli (house),

 tochtli (rabbit) 

and acatl (reed) 

which are arranged in thirteen permutations. Those images helped the researchers match some pictorial accounts of quakes, including one in 1507, to later descriptions of the events.

     Little more is recounted about the precise locations of these quakes or the damage they caused, although one image suggests that a quake triggered flooding that drowned several warriors. Other codices may contain more clues, the researchers say, which could help create a more complete chronology of the quakes that shook this part of the Americas."

Knife, house, rabbit, reed?

Codex Steph

Shoo, Shoo Shuvuuia: Nocturnal Owl-Like Dinosaur with Keen Eyesight and Acute Hearing

            A small  carnivorous dinosaur had superb low-light vision and hearing that was likely as good as an owl's. And like an owl, the tiny dinosaur probably used those exceptional abilities to stalk and catch its desert prey under the cover of darkness.

    The owl-like Shuvuuia (shu-VU-ya) was a theropod, a three-toed and bipedal carnivorous dinosaur. There's only one known species, Shuvuuia deserti, and it was smaller than a domestic cat, measuring 2 feet (0.6 meters) long. Shuvuuia lived about 75 million to 81 million years ago, during the late Cretaceous period in what is now the Gobi Desert in Mongolia.

      Prior analysis of Shuvuuia's fossilized eye bones revealed that it had large eyes that were specialized for seeing in dim light. But at the time, little was known about dinosaur adaptations for nocturnal activity. In a new study presented May 7, 2021 in Science, researchers looked at skulls from dozens of species of extinct theropods and modern birds, the only theropod lineage that survived to the present.

      By comparing dinosaurs' fossilized eye and ear structures with those in living animals that have nocturnal habits, the researchers were able to see if a dinosaur was adapted for day or night activity.

        Soft tissue is rarely preserved in the fossil record, but paleontologists can find clues about dinosaurs' eyes and vision in the bones that form a circle in the eye socket, known as the scleral ring. Scleral rings are found in many vertebrates (including extinct dinosaurs), and the diameter of this ring reveals the maximum width that an animal's pupil can dilate, hinting at their ability to see in low light, said lead study author Dr. Jonah Choiniere, University of the Witwatersrand in Johannesburg.  

     But nighttime hunting doesn't just depend on having good eyesight; specialized hearing is also key. So the researchers examined ear anatomy in 88 bird species and 17 extinct fossil theropods, using computed X-ray tomography (CT) scans to construct digital 3D models of the animals' skulls. They paid close attention to the cochlea, the part of the inner ear canal that holds sensory receptors for picking up sound waves. Decades of previous research had shown that the length of this canal is closely linked to how well animals can hear, and the length of Shuvuuia's ear canal suggested that its hearing would have been "off the charts," Dr. Choiniere said.

      "Shuvuuia had proportionally longer cochlear ducts than even the bird with the best hearing, the barn owl," Dr. Choiniere continued. What's more, the size of Shuvuuia's scleral rings showed that it also possessed "incredible night vision — better than any living bird we measured," he added. 

      The combination of light-sensitive eyes and superior hearing suggested that Shuvuuia would have been highly effective at detecting and ambushing prey at night, as owls do. By comparison, the theropod Velociraptor, which lived in the Gobi Desert alongside Shuvuuia, had an intermediate eye shape, "and was probably more twilight-active," said study co-author Dr. Lars Schmitz, W.M. Keck Science Department at Scripps College, CA. This is the first time that such extreme specializations for hearing and vision have been documented in an extinct dinosaur; in combining vision with hearing, the study also provides the best evidence for nocturnal behavior in dinosaurs, Dr. Schmitz said. 

     With a "hodgepodge body" Shuvuuia was an odd-looking dinosaur, and though it's related to fearsome meat-eating theropods such as Velociraptor and Tyrannosaurus rex, "it's totally unlike them," Dr. Choiniere said. "It's got a lightly built jaw, and its teeth look like tiny grains of basmati rice. It's got this massive eye, but the beak is very small," he said. Shuvuuia's forelimbs were powerful and bulky, tipped with a huge claw like an aardvark's. Capping off this hodgepodge of features was a pair of long, slender hind legs that were built for running. Shuvuuia deserti may have preyed on nocturnal desert insects. Shuvuuia deserti may have preyed on nocturnal desert insects. 

      However strange its body may have looked, these traits may have made Shuvuuia a better nighttime hunter. Some modern mammals that live in arid desert environments, as Shuvuuia did, combine lengthy hind limbs with digging forelimbs, "and they often have really good night vision and hearing," which helps them track and catch hard-to-find prey, Dr. Choiniere said. Burrowing desert prey would also be an easy meal for Shuvuuia to dig up with its powerful forearms. "This observation that Shuvuuia could have operated at night makes a lot of sense in light of the rest of the adaptations," he said. "It puts those into perspective and allows us to think it would have fit into a desert ecosystem today really well." 

      Animals that live together in the same geographical location often require the same resources in order to survive, but they can share them by being either night owls or early birds. Dinosaurs likely did this as well, and this study is just the beginning of paleontologists' discoveries of nocturnal and daytime preferences in these extinct animals and how those preferences might have affected their habits and behavior, Dr. Schmitz said. "That's something that we really don't understand well yet in the fossil record, but we know from looking at living species," he said. "I think there are some exciting discoveries waiting to be made."

         I wonder why we usually use birds to define early morning or late night behaviors. Which are you?