1) Chondrites isp. Erected by Sternberg [35] . It is a dendritically complex burrow system, consisting of asymmetrical and branching smooth-walled tunnels. The Chondrites tunnels have a circular cross-section view.

2) Cruziana. Erected by Alcide D’Orbigny [36] . The burrow consists of elongate, and bilaterally symmetrical morphology. The burrow is preserved along bedding planes, with a sculpture of repeated striations that are mostly oblique to the long dimension.

3) Fugichnia. Erected by Simpson [37] . The burrow is an escape structure, which has the shape of chevron pattern showing the upward direction the organism tunneled through in responds to sudden, episodic, or high sedimentation events.

4) Planolites montanous isp. Erected by Nicholson [38] . Burrows are horizontal to sub-horizontal, unlined, un-branched, and small diameter ~ 2 mm. The shape of the burrow is sinuous, to tortuous, and circular to elliptical in cross-section. Burrow filled are structureless, and differ from the host rock/sediment. Walls are mostly smooth.

5) Skolithos linearis. Erected by Haldeman [39] . Burrows are straight, cylindrical to curved, distinctly smoothed walled, rarely branched, and vertical to steeply inclined. Unornamented simple shafts are mostly retrusive and merge upward at various angles with bedding planes.

6) Thalassinoides suevicus. Erected by Reith [40] . Burrow system is pre-dominantly horizontal and regularly branched. They form bedding-parallel mazes. Branches ramify at acute angles. The Y-shaped dichotomous bifurcations dominate T-shaped branches. The branches are cylindrical in shape and circular to oval shape in transverse section.

7) Teichichnus rectus. Erected by Seilacher [41] . Vertical and unbranched spreite consist of tightly packed, straight to broadly U-shaped laminae. Burrows have variable dimensions. Longitudinal sections show nested burrows of simple, long, straight to sinous, upward migrated, horizontal to sub-horizontal tunnels. These tunnels are mostly retrusive and merge upward at various angles with bedding planes.

8) Phycosiphon. Erected by Von Fisher-Ooster [42] . The structure is irregularly meandering, black-colored burrows with a pale holo of coarse silt. In cross-section, the burrows are elliptical to sub-circular, U-shaped in the longitudinal profile. Burrow structure is normally erratic, vermicularly tanged. In core, it commonly appears as tiny dark pin-head sized spots. In longitudinal cross-section, it shows discontinuous and surrounded by a pale silt halo.

9) Palaeophycus. Erected by Hall [43] . The structure is straight, slightly curved, slightly undulose or flexuous, smooth or ornamented, typically lined, essentially cylindrical, predominantly horizontal structures interpreted as open burrows; burrow-fill typically massive, similar to host rock, although substantial fill may be absent; where present, bifurcation is not systematic, nor does it result in swelling at the sites of branching. The structures is characterized as passively filled, typically lined, burrows [44] .

10) Zoophycos. Erected by Massalongo [45] . Burrow is a circular to lobate sheet-like spreite; either flat, curved, inclined or wound in screw fashion around a central vertical axis. The spreite is a horizontal or sub-horizontal web of closely juxtaposed parallel burrow tunnels. Burrow tunnels system show the path of feeding apparatus during a single probing of the sediment. Successive probing side-by-side in the same direction or plane produces a horizontal spreite.