Answer:
500-million-year-old fossil found in BC is ancient ancestor of spiders and scorpions. Palaeontologists in British Columbia have found a fossil of the oldest known ancestor of scorpions and spiders.
The serous fluid within the pericardial cavity works to lubricate the membranes of the serous pericardium. It is the space between the layers of the pericardium.
<h3>What is the pericardial cavity?</h3>
The pericardial cavity refers to the space between different layers of the pericardium in the heart.
The pericardium is one of the three tissues that form the heart (i.e., pericardium, myocardium, and endocardium).
The pericardial cavity is composed of a serous fluid capable of reducing surface tension and lubricating this layer.
Learn more about the pericardial cavity here:
brainly.com/question/2833911
The most common condition is whether or not there is a source of water on the planet
