Camera hovering over gentle waves in the middle of a quiet sea, no visible land on the horizon, sunny day.
Plunge, continuous and steady descent in clear bluish-greenish waters, sun rays penetrating deep below the surface.
Top edge of a submarine cliff in the depths (representing the Cathedral Escarpment – See Research Contributions from GSC Geological Studies in the History Section), first perceptible as a faint shadow, becomes increasingly clear. Meadows of the algae Margaretia can be seen in the distance, with their elongate tubes gently undulating in the currents.
Camera nears the edge of the cliff, and starts its descent alongside into increasingly deeper and darker waters. Indistinct algae growing along the near vertical walls of cliff.
Dozens of metres below, close to the bottom of the cliff, a black shadow recognizable as the arthropod Odaraia, swims at a fair distance from camera, and moments later a second individual quickly passes in front of field of view at shorter range.
As features of the seafloor start appearing in the dim light, the largest arthropod in the Cambrian sea, Anomalocaris,swims away above ghostly shapes of sponges, presumably in search of prey.
As the eyes adjust to the low light conditions, clusters of sponges can be seen along the seafloor, ranging far into the distance. Powerful spotlights are turned on, illuminating a nearby group of tall sponges.
Final metres, slower descent. A primitive cephalopod, Nectocaris, can be seen hovering just in front of camera apparently unperturbed. When spotlights are redirected towards the foreground, Nectocaris swims quickly backwards, using its lateral fins and funnel (by jet propulsion), before disappearing out of the field of view. Several individuals of the small arthropod Marrella can be seen swimming away from camera as well.
Full stop between patches of sponges. This area teems with life, either moving or attached to the seafloor. The surface of the soft muddy sediment is littered with small shelly debris and disarticulated arthropod elements (including an Anomalocaris claw, probably representing a molt). Sponges of various shapes, sizes and colors, including Hazelia, Pirania and Wapkia, and algae such as Waputikia and Yuknessia, can be recognized. A primitive mollusc, Wiwaxia, is seen moving very slowly, at the bottom of a group of sponges. Fossils of all these organisms are found today in the Walcott Quarry, but they represent just a fraction of the once-living community (see the Locality Today and the Walcott Quarry Community in the Science Section – Burgess Shale)
End of sequence.
Total length = 60 sec.