Shark evolution discoveries

This video from Australia says about itself:

Why does one kind of turtle escape hungry tiger sharks, but another doesn’t? National Geographic’s Crittercam® helps researchers find out how one turtle species stays off the shark’s dinner menu.

The six-foot-long babies of the world’s biggest shark species, Carcharocles megalodon, frolicked in the warm shallow waters of an ancient shark nursery in what is now Panama, report palaeontologists working at the Smithsonian Tropical Research Institute and the University of Florida: here.

Great whites ‘not evolved from megashark’: here.

The ancestor of all hammerhead sharks probably appeared abruptly in Earth’s oceans about 20 million years ago and was as big as some contemporary hammerheads, according to a new study led by the University of Colorado at Boulder: here.

No more eating shark fin in Hawaii after new law: here.

Shark Science on the 35th Anniversary of Jaws: Great white sharks are mysterious and dangerous. And cool: here.

Deepwater Shark Diets Include Other Sharks: here.

Tiger Shark Feeding Frenzy Captured on Video: here.

Soon you will have your chance to bid on a massive Megalodon jaw, measuring 11 feet across and 8.5 feet high: here.


Azendohsaurus is not a dinosaur

This is a reconstruction of the skull of the new species of Azendohsaurus. On top is a lateral or side view, and on the bottom, a palatal or roof of the mouth view. Note the teeth covering the palate, a highly unusual feature among reptiles, and the downturned front end of the lower jaw, a feature found independently in many herbivorous archosauromorphs. Credit: S. Nesbitt

From the American Museum of Natural History:

Demoting a dinosaur

New fossil material redefines Azendohsaurus as a peculiar early reptile

Azendohsaurus just shed its dinosaur affiliation. A careful new analysis of A. madagaskarensis—this time based on the entire skull rather than on just teeth and jaws—aligns this 230-million-year-old animal with a different and very early branch on the reptile evolutionary tree. Many aspects of Azendohsaurus are far more primitive than previously assumed, which in turn means that its plant-eating adaptations, similar to those found [among] some early dinosaurs, were developed independently. The new analysis is published in the journal Palaeontology.

“Even though this extraordinary ancient reptile looks similar to some plant-eating dinosaurs in some features of the skull and dentition, it is in fact only distantly related to dinosaurs,” says John J. Flynn, curator in the Division of Paleontology at the American Museum of Natural History. “With more complete material, we re-assessed features like the down-turned jaw and leaf-shaped teeth found in A. madagaskarensis as convergent with some herbivorous dinosaurs.”

The fossil is a member of Archosauromorpha, a group that includes birds and crocodilians but not lizards, snakes, or turtles. The type specimen of the genus Azendohsaurus was a fragmentary set of teeth and jaws found in 1972 near (and named for) a village in Morocco’s Atlas Mountains. The fossils on which the current research paper is based was discovered in the late 1990s in southwestern Madagascar. Named A. madagaskarensis, this specimen was uncovered by a team of U.S. and Malagasy paleontologists in a “red bed” that includes multiple individuals that probably perished together. This species was initially published as an early dinosaur in Science over a decade ago, but the completeness of the more recently unearthed and studied fossils has provided the first complete glimpse of what this animal looked like and was related to. A. madagaskarensis was not a dinosaur.

A. madagaskarensis lived during the period of time that dinosaurs, crocodile relatives, mammals, pterosaurs, turtles, frogs, and lizards were getting their start, and all of the continents were connected as the supercontinent Pangaea. A. madagaskarensis was 2 to 4 meters long and weighed between 20 and 50 kilos (about 44 to110 pounds). A. madagaskarensis was an efficient herbivore—”a veritable four-legged weed-whacker,” according to Flynn—with teeth modified for slicing vegetation covering not only its jaws, but also the roof of its mouth. Even though early archosaurs were commonly thought to be primarily carnivorous, A. madagaskarensis shows that traits associated with herbivory were much more widespread across archosaur reptiles.

“Now there are many more cases of herbivorous archosaurs,” says André Wyss, professor at the University of California, Santa Barbara. “We are rethinking the evolution of diet and feeding strategies, as well as the broader evolution of the group.”

“This is the way science works,” says Flynn, commenting on the reinterpretation of the fossils. “As we found and analyzed more material, it made us realize that this was a much more primitive animal and the dinosaur-like features were really the product of convergent evolution.”

Wyss adds, “In many ways Azendohsaurus ends up being a much more fantastic animal than if it simply represented a generic early dinosaur.”

Batrachotomus kupferzellensis was an extinct archosaur (an ancestor of dinosaurs), the only species of its genus. It lived in the middle of the Triassic Period in Europe, about 237-228 million years ago. So, it surely coexisted with the first primitive dinosaurs. Its first fossils were found by Johann Wegele, a fossil collector, in Kupferzell, Baden-Wurttemberg, Germany, in 1977, but they were named only in 1999 by David J. Gower.

An unusual new archosauriform from the Middle–Late Triassic of southern Brazil and the monophyly of Doswelliidae: here.

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Lesbos, last morning

Today is 11 May, our last morning on Lesbos, after our last complete day, 10 May.

A common tern sitting near the wetland water.

A crested lark.

A singing black-headed bunting.

As the bus drives past Kalloni village, our second Lesbos coot in a ditch.

Four bee-eaters flying.

This is a bee-eater video.

At 12:25, our plane takes off. At 12:32, we pass Sigri, the far west of Lesbos.

14:05 West European time, we are near Dortmund in Germany.

At 14:18, we fly over the Naardermeer nature reserve and over Naarden, the old fortress town.

At 14:30, we land. An oystercatcher is the first bird which we see.

Krüper’s nuthatches and orchids

After the early morning of 10 May, our bus heads to the east of Lesbos island.

We pass the salt pans. In a coastal wetland more to the east, little egrets, grey herons, and ruddy shelducks.

Near a parking lot is a tree which is missing its upper half. It supports an electricity wire. And, most importantly: two Krüper’s nuthatches are nesting in it. This rare songbird lives only in Turkey and Lesbos.

This is a Krüper’s nuthatch video, recorded on Lesbos island.

Every now and then, the birds enter or leave the nest hole. One sits down on a branch to clean its feathers.

A masked shrike on the electricity wire.

A male chaffinch on the forest floor.

Further inland, near Agiasos, a rare orchid grows along the forest road: Comperia comperiana.

Blackbird and subalpine warbler singing.

A male serin sings, while the female serin builds their nest. European serin photos are here. And here.

Another orchid: white helleborine.

About orchids on Lesbos: here.

A cuckoo sound. Soon, we are back in the wetland between Achladeri and the Kalloni salt pans.

Ruddy shelducks. Great and little egrets. Many crabs and fish, brought in by the marine high tide.

Our last visit to the salt pans.

A squacco heron. Little stints.

Greater flamingos.

A lone black-tailed godwit.

Big caterpillars on fennel plants. They are of old world swallowtail butterflies.

This morning, someone has seen small pincertail dragonfly.

Rare British orchid gets police protection from overzealous collectors: here.

The breeding pairs of the Algerian Nuthatch have been censused in the Guerrouch forest (Taza National Park, Jijel, Algeria). A decrease in numbers was assessed when comparing with data collected in the early 1990s. The main reason is the habitat degradation by human activities. First data were obtained by studying a nest located in a Zeen Oak. The clutch size was of 6 eggs. Incubation time was estimated to last 17 days and the nestling period likely to last 21 days. The breeding season stretched from April to early June. No evidence of second clutch: here.

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Goldfinch and marsh harrier

After 9 May, 10 May. Our last full day on Lesbos island.

Cetti’s warbler.

A female marsh harrier flying over the wetland.

A black-headed wagtail on the old Christou river bridge.

A Kentish plover on the pebbles near the river.

A goldfinch on a bush.

A singing corn bunting, and a singing black-headed bunting.

Crested larks and house martins.

Stripe-necked terrapins and fish in the Christou river.

This is a stripe-necked turtle video.

Red-footed falcons and avocets

This is a red-footed falcon video.

After the morning of 9 May on Lesbos, the afternoon.

Like on 5 May, to the salt pans.

Again, avocets and black-winged stilts. An avocet chick.

Pale (juvenile) and pink (adult) greater flamingos.

Flying little egrets and black storks.

A ringed plover.

A male and a female red-footed falcon, sitting together on a telephone pole. The male is cleaning its feathers. At first, it sits to the right of the female; then, to the left.

Two turnstones and ruffs on a dike.

A little tern sitting on a rock.


Little stints, where there were Temminck’s stints last time. A common sandpiper.

At the glossy ibis marsh, a collared pratincole in the grass.

A coot in the water. It is the first one we have seen; this species is rare in Lesbos.

Wood sandpipers.

Whiskered terns.

A squacco heron standing between the common spike-rush.

Curlew sandpipers.

A mallard. Again a first for us on Lesbos, as this species is rare here.

A little ringed plover.

Dark spreadwing damselflies flying around.

A whinchat sitting on a fence.