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New Zealand’s ancient monster penguins had northern hemisphere doppelgangers – Phys.org

New Zealand’s Ancient Monster Penguins had Northern Hemisphere Doppelgangers
Plotopterids like these Copepteryx looked remarkably like penguins. Credit: Mark Witton. Available for media and current affairs use; all other rights reserved

New Zealand’s monster penguins, which lived 62 million years ago, had doppelgangers in Japan, the U.S. and Canada, a study published today in the Journal of Zoological Systematics and Evolutionary Research has found.

Scientists have identified striking similarities between the ‘ fossilized bones and those of a group of much younger Northern Hemisphere , the plotopterids.

These similarities suggest plotopterids and ancient penguins looked very similar and might help scientists understand how birds started using their wings to swim instead of fly.

Around 62 million years ago, the earliest known penguins swam in tropical seas that almost submerged the land that is now New Zealand. Paleontologists have found the fossilized bones of these ancient waddlers at Waipara, North Canterbury. They have identified nine species, ranging in size from small penguins, the size of today’s Yellow-Eyed Penguin, to 1.6-meter-high monsters.

Plotopterids developed in the Northern Hemisphere much later than penguins, with the first species appearing between 37 and 34 million years ago. Their fossils have been found at a number of sites in North America and Japan. Like penguins, they used their flipper-like wings to swim through the sea. Unlike penguins, which have survived into the modern era, the last plotopterid species became extinct around 25 million years ago.

Dr. Gerald Mayr of the Senckenberg Research Institute and Natural History Museum, Frankfurt, James Goedert of the Burke Museum of Natural History and Culture and University of Washington, U.S., and Canterbury Museum Curators Dr. Paul Scofield and Dr. Vanesa De Pietri compared the fossilized bones of plotopterids with fossil specimens of the giant penguin species Waimanu, Muriwaimanu and Sequiwaimanu from Canterbury Museum’s collection.

They found plotopterids and the ancient penguins had similar long beaks with slit-like nostrils, similar chest and shoulder bones, and similar wings. These similarities suggest both groups of birds were strong swimmers that used their wings to propel them deep underwater in search of food.

New Zealand’s Ancient Monster Penguins had Northern Hemisphere Doppelgangers
The giant penguins, like these Kumimanu, that lived in Aotearoa New Zealand around 60 million years ago bore a striking resemblance to some plotopterids. Credit: Mark Witton. Available for media and current affairs use; all other rights reserved

Some species of both groups could grow to huge sizes. The largest known plotopterids were over 2 meters long, while some of the giant penguins were up to 1.6 meters tall.

Despite sharing a number of physical features with penguins both ancient and modern, plotopterids are more closely related to boobies, gannets and cormorants than they are to penguins.

“What’s remarkable about all this is that plotopterids and ancient penguins evolved these shared features independently,” says Dr. De Pietri. “This is an example of what we call , when distantly related organisms develop similar morphological traits under similar environmental conditions.”

Dr. Scofield says some large plotopterid species would have looked very similar to the ancient penguins. “These birds evolved in different hemispheres, millions of years apart, but from a distance you would be hard pressed to tell them apart,” he says. “Plotopterids looked like penguins, they swam like penguins, they probably ate like penguins—but they weren’t penguins.”

Dr. Mayr says the parallels in the evolution of the bird groups hint at an explanation for why birds developed the ability to swim with their wings.

“Wing-propelled diving is quite rare among birds; most swimming birds use their feet. We think both penguins and plotodopterids had flying ancestors that would plunge from the air into the water in search of food. Over time these ancestor got better at swimming and worse at flying.”

Fossils from New Zealand’s giant penguins, including Waimanu and Sequiwaimanu are currently on display alongside life-sized models of the birds in Canterbury Museum’s exhibition, “Ancient New Zealand: Squawkzilla and the Giants,” extended until 16 August 2020.

Comparative osteology of the penguin-like mid Cenozoic Plotopteridae and the earliest true fossil penguins, with comment on the origins of wing-propelled diving, by Gerald Mayr, James L Goedert, Vanesa De Pietri and R Paul Scofield is published in the Journal of Zoological Systematics and Evolutionary Research.



More information:
Journal of Zoological Systematics and Evolutionary Research, DOI: 10.1111/jzs.12400

Citation:
New Zealand’s ancient monster penguins had northern hemisphere doppelgangers (2020, June 30)
retrieved 1 July 2020
from https://phys.org/news/2020-06-zealand-ancient-monster-penguins-northern.html

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ancient Roman

An ancient Roman city has been fully mapped using ground-penetrating radar – Ars Technica

What lies beneath —

Archaeologists have found a monument, market, temple, bath complex, and water pipes.


Ground-penetrating radar map of the temple in the Roman city of Falerii Novi, Italy.

Enlarge / Ground-penetrating radar map of the temple in the Roman city of Falerii Novi, Italy.

L. Verconck

Falerii Novi was once a walled town just north of Rome, likely founded around 241 BC as a relocation site for a Falisci tribe that had rebelled against the Romans. Located on a volcanic plateau, archaeologists surmise that the new site was chosen because it wasn’t as easy to defend, thereby discouraging further uprisings. There were likely some 2,500 residents during the third and fourth centuries BC. The ruins are deep underground, but a team of archaeologists from the University of Cambridge and Ghent University in Belgium have used ground-penetrating radar (GPR) to map the complete city. They described their findings in a recent paper in the journal Antiquity.

Dating back to 1910, when the first patent for a radar system to locate buried objects was filed, GPR has been used to measure the depth of glaciers, to study bedrock and groundwater, and to locate unexploded land mines, buried sewers, and utility lines, among other applications. The 1972 Apollo 17 mission—the final moon-landing mission of NASA’s Apollo program—used a GPR system called the Apollo Lunar Sounder Experiment (ALSE) to record depth information of the lunar surface. The method has also emerged in recent years as a powerful tool for archaeological geophysics, since it is a non-invasive means of detecting and mapping artifacts, features, and key patterns beneath the surface.

GPR is distinct from another popular method, LIDAR, which relies on infrared light from lasers rather than radio waves to map terrain. An electromagnetic pulse is directed into the ground, and any objects or layering (stratigraphy) will be detectable in the reflections picked up by a receiver, just like regular radar. How long it takes for the echoes to return indicates the depth, and different materials will reflect the incoming waves differently. The data can then be plotted to create detailed maps of those underground features.

Falerii Novi was first excavated in the 1990s, and over the ensuing decades archaeologists have identified warehouses, shops, market places, a theater, and a forum using various non-invasive techniques, including magnetometry—a method that measures the direction, strength, or relative change of a magnetic field at a given location to reveal details beneath the surface. But the use of GPR by the British and Belgian team has yielded a much more detailed and complete picture of the site, enabling them to study how the town evolved over several hundred years.

The authors attached their GPR system to the back of an ATV in order to more efficiently survey the 30.5 hectares (about 75 acres) within the ancient city’s walls, taking a reading every 12.5 centimeters. In 2017, using their method, the team found the remains of a large Roman temple, several feet below the town, that would have been roughly the same size as St. Paul’s Cathedral.

  • Map showing the location of the ancient Roman city Falerii Novi, in Italy.


    Lieven Verdonck

  • Co-author Lieven Verdonck and his colleagues attached a ground-penetrating radar system to the back of a “quad bike” to better map the excavation site.


    Lieven Verdonck

  • A slice of GPR data from Falerii Novi revealing the outlines of the town’s buildings.


    Lieven Verdonck

  • The porticos duplex and public monument to the east of Falerii Novi’s north gate.


    Lieven Verdonck

  • GPR map of the theater.


    Lieven Verdonck

This latest analysis revealed a large rectangular structure connected to a network of water pipes, leading to the city’s aqueduct. The authors surmise that it is the remains of an open-air pool (natatio), part of a large public bathing complex. They were also surprised to see two large structures facing each other within a covered passageway (porticus duplex) that they believe was once part of a large public monument near the city’s north gate. It seems to be part of a “sacred topography” of temples around the town’s periphery, previously revealed by magnetometer surveys.

GPR works very well in certain conditions, like uniform sandy soils, but the high electrical conductivity of clays and silts, for example, can significantly dampen signal strength. And rocky sediments will scatter the signal, making it more difficult to pick out the patterns in the noise. “At Falerii Novi, the generally dry conditions in the summer months were well-suited to GPR survey,” the authors wrote, noting, however, that when it did rain, “up to seven days were needed before the ground was sufficiently dry to yield optimal data quality.”

Falerii Novi was a good site to demonstrate the potential of GPR because it is not buried beneath modern buildings, unlike other ancient cities. GPR, particularly when combined with magnetometry, could be a useful tool to study such towns. “Neither [GPR or magnetometry] is able to produce a complete picture of the archaeology,” the authors wrote, noting that the shop units of Falerii Novi, for example, show up in the magnetic data but not in the GPR survey. And while the city’s theater shows up in the magnetic data, the GPR survey provided a much clearer view, including at different depths, yielding insight into its structural form, as well as evidence of the removal of walls via stone-robbing.

The biggest challenge going forward is the sheer amount of data produced by this high-resolution mapping. According to the authors, they have collected a whopping 71.7 million readings from Falerii Novi, equivalent to 28.68 billion data points, or about 4.5GB of raw data per hectare (2.47 acres). It can take as long as 20 hours to document a single hectare, which is why the team is developing automated techniques to speed up the process with computer-aided object detection.

“The astonishing level of detail which we have achieved at Falerii Novi, and the surprising features that GPR has revealed, suggest that this type of survey could transform the way archaeologists investigate urban sites, as total entities,” said co-author Martin Millett of the University of Cambridge, adding that it should be possible to use GPR to survey major ancient cities like Miletus in Turkey, or Nicopolis in Greece. “We still have so much to learn about Roman urban life, and this technology should open up unprecedented opportunities for decades to come.”

DOI: Antiquity, 2020. 10.15184/aqy.2020.82  (About DOIs).

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