Creature features
A microscopic human ancestor and an outsized amphibian
ANCESTRAL OLD BAG
A team of British scientists has announced in the journal Nature that humanity’s earliest known evolutionary ancestor is a 1mm creature resembling a “wrinkled old sack” that spent its life “wriggling around” on the ocean floor 540 million years ago. One of its most intriguing features was an apparent lack of an anus, meaning it ate and excreted from the same large aperture. The fossil was unearthed in Shaanxi province, China, and named Saccorhytus coronarius. The team had to crunch through three tonnes of limestone to find just 45 of the microfossils. Their discovery means we can now trace our roots back a further 30 million years. The creature is thought to be the most primitive example of the deuterostome, a category of animal life from which vertebrates eventually emerged. Most other early deuterostome groups date from about 510–520 million years ago, when they had already begun to diversify into vertebrates, and animals like sea squirts, starfish, sea urchins and acorn worms.
Simon Conway Morris, professor of evolutionary palæobiology at Cambridge, said: “To the naked eye, the fossils we studied look like tiny black grains, but under the electron microscope the level of detail is jaw-dropping. All deuterostomes had a common ancestor, and we think that is what we are looking at here.” The creature’s body was symmetrical, a characteristic inherited by many of its evolutionary descendants, including humans. It was covered with a thin, flexible skin, suggesting it had some form of muscles, leading researchers to conclude that it got around by wriggling. The small conical structures on its body may have allowed swallowed water to escape, and so were perhaps the precursor of gills. D.Telegraph, Guardian, D.Mail, 31 Jan 2017.
GIANT FROG SPOTTED
In March 2013 a strange creature was seen crawling out of Lake Itasca in north-central Minnesota. The state is known as “the land of 10,000 lakes”; the actual figure is 11,842. Lake Itasca is less than two square miles in area and has a depth of around 35-40ft (11-12m). The witness was ‘Don’, a keen outdoorsman who was strolling along the lakeshore with his German shepherd dog Ben when he noticed a disturbance in the water at a distance of around 50ft (15m). As he got closer, he was stunned to see a huge frog crawl out of the water and, for a couple of seconds, peer intently and eerily in his direction. It was truly enormous: Don reckons about 4ft (122cm) in length. He thought about taking a picture with his iPhone, but before he could do so, the creature flopped back into the water with a powerful splash, and was gone.
Don spent the entire day and night staking out that area of the lake, but the beast did not return. Monster-hunter Ken Gerhard said: “Back in 1995, there were an incredibly large number of deformed frogs that were found in a pond in southwest Minnesota. It made big national news. It was looked at as a sign of the times: there was so much pollution that man’s impact on the environment was causing these really bizarre frog mutations.” The US Geological Survey said: “Malformations included missing limbs, missing digits, extra limbs, partial limbs, skin webbing, malformed jaws, and missing or extra eyes… It is likely that one or more combinations of chemicals, biological, and physical factors are responsible for causing the malformations in Minnesota frogs.” Whether these factors could lead to a frog the size of an Alsatian is a bit of a stretch. All we can hope for is another sighting… mysteriousuniverse.org, 4 Oct 2016.