This year, we've had a record 150,000 children homeless in England.

We'll be waking up homeless on Christmas morning, in cramped rooms, with nowhere to play,

and sometimes even having to share bathrooms with strangers.

This is not a home.

This is the heartbreaking reality, but it doesn't have to be this way.

Your donation to shelter could help a family find a safe place to call home.

Donate today at shelter.org.uk.

Welcome to this audio long read from nature.

In this episode, these bizarre ancient species are rewriting animal evolution,

written by Tracy Watson and read by me, Benjamin Thompson.

The revolutionary animal lived and died in the muck.

In its final hours, it inched across the seafloor, leaving a track like a tire print, and

finally went still. Then geology set to work. Over the next half a billion years, sediment turned to stone, preserving the deathbed scene.

The fossilised creature looks like a piece of frayed rope measuring just a few centimetres wide,

but it was a trailblazer among living things. This was the earliest known animal

to show unequivocal evidence of two momentous innovations packaged together, the ability to roam

the ocean floor and a body built from segments. It was also among the oldest known to have clear front and back

ends and a left side that mirrored its right. Those same features are found today in

animals from flies to flying foxes, from lobsters to lions.

Paleontologist Shuai Zhao marvels at the tracks left by this creature,

Yalingia, Spicy Formis, and how they captured evidence of its movement.

In his cluttered office at Virginia Tech in Blacksburg, he shows off a slab of beige resin,

...