#early neogene

[saritapaleo]

Archovember 2024 Day 19 - Pelagornis sandersi

After the K-T extinction, the last remaining dinosaurs began to diverge, trying on many different shapes and sizes. While most birds stayed in the small forms that had kept them alive for so long, some achieved massive sizes. Some even reached these sizes while still retaining their ability to fly. One such genus was Pelagornis, a group of “pseudotooth birds.” While the gene for teeth was lost in birds, the Pelagornithids found a work-around, evolving tooth-like edges to their beaks. These were seabirds, using their saw-edged beaks to grip onto slippery fish and squid. The largest species of Pelagornis was Pelagornis sandersi. P. sandersi was not only the largest Pelagornis, but also had the widest wingspan of any known bird, estimated at 6.06 to 7.38 m (19.9 to 24.2 ft) long. P. sandersi had short, stumpy legs, and likely spent most of its time on the wing. It would have had to take off by dropping from cliffs, utilizing air currents to glide into the air. It would have been able to travel long distances like this, without landing, similar to modern day albatrosses.

Fossils of Pelagornis have been found worldwide, including in the Aridal Formation of Morocco, the Chandler Bridge Formation of South Carolina, the Bahía Inglesa Formation of Chile, the Black Rock Sandstone of Australia, the Molasse Coquilliere Formation of France, the Calvert Formation in Virginia, the Pisco Formation of Peru, the Castillo Formation and Capadare Formation of Venezuela, the Greta Formation of New Zealand, and the Purisima Formation of California. This worldwide distribution means they would have been living alongside a large variety of Eocene to Early Pleistocene animals, and eating a large variety of fish species. It is unknown why these giant seabirds went extinct, but they may have been encountered by archaic humans in the Early Pleistocene.

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[saritapaleo]

Archovember 2024 Day 22 - Purussaurus brasiliensis

Long, long after Deinosuchus ruled Late Cretaceous North America, and longer still after Sarcosuchus ruled Early Cretaceous Africa and South America, Purussaurus brasiliensis began its reign. Purussaurus was a giant caiman from Miocene (Early Neogene) South America. Oddly enough, so far only skulls have been found, and its body length has been estimated at anywhere from 7.6–9.2 metres (25–30 ft) to 9.9–15.8 metres (32–52 ft)! However, its skull itself is smaller than Deinosuchus’, so these estimates take into account the longer body length of caimans. Either way, Purussaurus was the largest crocodilian of its time, and would have preyed on large Miocene mammals, using the death roll like modern crocodilians to subdue its prey. Its large size may have eventually been its downfall, as it was harder for it to adapt to a changing environment, while the smaller caimans lived on.

Purussaurus brasiliensis has been found in the the Solimões Formation, the Castilletes Formation, the Culebra Formation, and the Socorro Formation. It would have preyed on a wide variety of Miocene animals across South America, including astrapotheriids like Hilarcotherium, protoceratids like Paratoceras, metatherians like Lycopsis, giant ground sloths, monkeys like Panamacebus and Solimoea, dugongs like Culebratherium, anhingas, and other caimans like Culebrasuchus.

This art may be used for educational purposes, with credit, but please contact me first for permission before using my art. I would like to know where and how it is being used. If you don’t have something to add that was not already addressed in this caption, please do not repost this art. Thank you!