Instantly fossilised? Lantern fruit into coal?

fossils coal fruits lantern Physalis infinemundiA delicate berry and its even more delicate lantern covering has not only been fossilized and discovered but has been partially turned to coal.

The lantern fruits are said to be 52 million years old.

How did they survive in the first place, how were these fragile fruit plants fossilized without apparently being destroyed and how were they transmuted to coal without being completely destroy?

Researchers found two fossils compressed into 52.2-million-year-old Patagonian stone, which showcased the flattened silhouettes of ancient lantern fruit … The fossils looked like two unique nightshade relatives in particular: ground cherries and tomatillos (the stuff salsa verde is made of), both of which are veiled in a papery husk. Veins of the husk are visibly detailed on the fossils, and scientists were even able to identify compacted remnants of the berry, which turned to coal during the fossilization process.
Tomato ancestor evolved 50 million years ago near Antarctica | American Association for the Advancement of Science

Especially as organic material converted to coal is meant to be transformed under great pressure deep under the surface?

Or could things be instantly fossilised where they are found?

A lot of the evolutionary history of life, especially plants, which are rare as fossils, is largely unknown.

Here we have this discovery of these incredibly rare, delicate fossils – here you have a berry surrounded by this papery calyx – it’s almost unheard of that such a thing could be fossilised.
Fossil fruit from 52 million years ago revealed | BBC

instantly fossilised

If the areas climate was much different, nearly the complete opposite, of todays wather then is this evidence of a dramatic event that perhaps changed the geology of the area and also not just turned the the Physalis infinemundi plant into a fossil but also transmuted it and the rock into the carbon element and coal?

Today, the site where the fossils were found, Laguna del Hunco in Argentina, is dry and desolate, but in the Eocene epoch (56 million to 33.9 million years ago), the area was near the shore of a caldera lake and had a much more tropical climate.
Tomato ancestor evolved 50 million years ago near Antarctica | AAAS