DiscoveRoss

Bipedal running has convergently evolved multiple times in squamate reptiles, known in over 50 modern species – and fossil evidence shows this is nothing new, with lizards repeatedly developing the ability to sprint on their hind legs for well over 100 million years.

Huehuecuetzpalli mixtecus here lived in east-central Mexico during the mid-Cretaceous, about 105 million years ago. About 25cm long (10"), it was part of an early branch of the iguanomorph lineage, related to the ancestors of modern lizards like iguanas, chameleons, and agamids.

Its limb proportions indicate it would have been a bipedal runner, making it one of the earliest known examples of this type of locomotion in lizards. Its skull also had some features convergent with varanids, suggesting it may have had a similar sort of active-pursuit-hunting ecology.

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Europe (Mediterranean - Detailed) - 293 BC

Map of Ottoman empire in early 16th century.

Variegated spring beegrabber, Myopa buccata, Conopidae (thick-headed flies)

Found mainly in western Europe, the larvae of this species are endoparasites of bumble bees.

Iridescent bark mantis adult and L6 nymph, Metallyticus splendidus, Metallyticidae. Found in Southeast Asia.

What if the first civilization arose in the Congo basin…100,000 years ago? The Rise of the River Kingdoms circa 100,000 BP by Prince di Corsica.

Map of Hong Kong and the New Territories, 1958.

[Species ] | Falkland steamer duck

Along with Cobb’s wren, the Falkland steamer duck (Tachyeres brachypterus) is one of two birds endemic to the Falkland Islands. It’s a large, flightless steamer duck, infamous for being rather aggressive.

The wings of Falkland steamer ducks are very short, which is true for all steamer ducks, which is why the name of their genus literally translates into short wing, brachy meaning short, and petron meaning wing. They use their wings for paddling instead of flying, which is how they got their common name, since they resemble old steamboats when moving across the water.

All steamer ducks look very much alike, making it difficult to distinguish between them in the field, especially since the one kind of steamer duck that can fly rarely does. An individual can reach up to 80 centimetres in length and weighs around 3,5 kilograms on average, with the drakes being significantly heavier than the hens. Other sexual differences include males having and overall paler plumage and looking less dull overall, which is likely a result of sexual selection.

Falkland steamer ducks sometimes feed in very shallow water, but still mainly dive to secure their prey, which consists of a variety of small marine animals, including snails, insect larvae and tiny fish. When a bird in a large flock dives, often most of the others also follow down at the same time.

The nest is a slight hollow in the ground, usually lined with grass and down feathers, placed either very close or directly next to the seashore, with exceptions confirming the rule by being placed up to 400 metres away. The female lays 5 - 8 eggs, incubating them all on its own, leaving the nest to bathe and preen for 15 to 30 minutes daily and covering up its eggs with materials before leaving.

With a stable population, but despite having a rather limited habitat, Falkland steamer ducks are considered birds of least concern, as they do not experience any major threats as of now and are considered to be locally common birds.

Europe in 1914, just before WW1 began.

(Skull reconstruction of Llukalkan aliocranianus, from Gianechini et al., 2021)

Meaning of name: Llukalkan = one who causes fear; aliocranianus = different skull

Age: Late Cretaceous (Santonian)

Where found: Bajo de la Carpa Formation, Neuquén, Argentina

How much is known: A partial skull, including a complete braincase.

Notes: Llukalkan was an abelisaurid ceratosaur, making it a close relative of genera like Carnotaurus and Aucasaurus. It lived alongside another abelisaurid, Viavenator, which is known from the partial skeleton of a slightly larger individual. However, Llukalkan differed from Viavenator in several anatomical details, most notably in the presence of a hollow depression in the back of the braincase that probably housed an air sac. As it is rare for air sac openings in the skeleton to be reduced during growth, the authors consider it unlikely that Llukalkan represents a specimen of Viavenator at a younger growth stage.

Expansion of Greece, 1832-1947.

Europe, 1444.