Historic family of penguins diversified shortly after the Cretaceous mass extinction occasion
MARK P. WITTON/SCIENCE PHOTO LIBRARY
4 new fossil species from New Zealand illustrate the hanging variety of the earliest penguins, which possessed lengthy, dagger-like beaks they could have used to skewer prey.
The brand new discoveries “present a surprising glimpse into the earliest evolution of penguins”, says Gerald Mayr on the Senckenberg Analysis Institute in Germany.
The fossils had been unearthed from the Waipara Greensand formation in Canterbury, New Zealand, which incorporates rock relationship again to between 62 and 58 million years previous. The formation is well-known for holding a number of the earliest chicken species that flourished and diversified after the mass extinction occasion that killed off all non-avian dinosaurs.
“We predict {that a} key characteristic of historical New Zealand was the absence of terrestrial predators, which enabled the lack of flight capabilities within the earliest penguins,” says Mayr. This lack of predators may clarify why some early penguins grew as giant as people, he says.
In complete, Mayr and his colleagues described 4 new species, which illustrate a broad variety in form and measurement. Most of the fossils comprise skeletal options that had been hitherto unknown, together with one specimen with abnormally lengthy hind toes and one other that had probably the most remarkably full cranium and beak of any early penguin.
“Fossils containing beaks, which might point out a chicken’s weight loss program, are extraordinarily uncommon for penguins from durations earlier than [23 million years ago],” says Tatsuro Ando on the Ashoro Museum of Paleontology in Japan, who wasn’t concerned within the research.
Dwelling penguins exhibit quite a lot of beak shapes which might be tailored to the particular prey they eat, which might vary from krill and small fish to invertebrates like squid, says Ando. These beaks may be quick, thick or curved, however none of those beaks are corresponding to these present in early penguins, that are lengthy and straight.
“The earliest penguins appear to have speared their prey with the lengthy beaks,” says Mayr. After skewering a fish, the penguin might need resurfaced from the water to throw it into the air and catch it, he says.
Penguins misplaced their elongated beaks after about 20 million years, which was in all probability an adaptation to extended diving durations underwater. As they adopted a extra aquatic life-style, their feeding methods and beak started to vary, too.
The brand new fossils assist present New Zealand was the “cradle of penguin evolution”, says Mayr, and the primary penguins diversified and dispersed from New Zealand to elsewhere all over the world like Antarctica, South Africa and far of South America.
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