DEATH ZONE 2: The Articulation Bone Unit, the layer immediately above the Bone Bed Unit
The Articulation Bone Unit. This next layer, which lies just above the Bone Bed layer, is where we have found and excavated fully and partially articulated Jurassic dinosaurs. As the close-up image of the juvenile Apatosaurus bones illustrates (left), this unit is the “home” of amazing specimens such as the big Camarasaurus and Straight Arrow Diplodocus.
Island or oxbow lake. Most likely a localized area, this zone was possibly an island or oxbow lake scenario. The land surface was surrounded by water or thick mud that was too deep for scavengers to cross so that they could feed on the dead dinosaurs. In fact, there is no evidence of scavenging on any of the bones within this layer.
Excellent preservation. This unit may also be partly time-equivalent to the lower Bone Bed Unit, as they appear to inter-finger in some areas of the digsite. The current interpretation is that the dinosaurs found died nearby and possibly bloated and floated during flooding events onto this higher semi-dry area. Carcasses either settled in or became entangled in downed/transported tree limbs or entire trees. Soon thereafter, the dinosaur remains were covered by subsequent flooding events, creating the perfect scenario for excellent preservation.
Island or oxbow lake. Most likely a localized area, this zone was possibly an island or oxbow lake scenario. The land surface was surrounded by water or thick mud that was too deep for scavengers to cross so that they could feed on the dead dinosaurs. In fact, there is no evidence of scavenging on any of the bones within this layer.
Excellent preservation. This unit may also be partly time-equivalent to the lower Bone Bed Unit, as they appear to inter-finger in some areas of the digsite. The current interpretation is that the dinosaurs found died nearby and possibly bloated and floated during flooding events onto this higher semi-dry area. Carcasses either settled in or became entangled in downed/transported tree limbs or entire trees. Soon thereafter, the dinosaur remains were covered by subsequent flooding events, creating the perfect scenario for excellent preservation.
