Flat Long-jawed Spider

Size 10mm body only, 50 including legs. This is an extremely common spider in my area. It is also a spider group that nobody seems to really know much about and admit it. Distinguishing features of the various species in the genus are vague/unclear, probably overlapping. I observed many different individuals lately. They are normally hard to spot. Luckily the spider tends to move when approached. Sometimes, it suddenly crawls on you because you might have disturbed its fine web or some silky strand. The animal crawls like a normal spider, but quickly returns into the stick posture, stretching legs to the front and the back, lowering its abdomen and thorax and staying motionless. They seem to be quite social, often with several individuals in the same area, probably even sharing the web. Their long-jaws can hardly be seen, even when checking for them. They simply align with the body or under the stretched out legs. I call this species Flat Long-jawed Spider since demissa means low-lying which accurately describes its behaviour.