| 词条 | Undichna britannica |
| 释义 |
| fossil_range = Silurian – ? | image = | image_caption = | taxon = Undichna britannica | authority = Higgs, 1988 }} Undichna britannica is a fish-fin, or fish-swimming fossil trackway left as a fossil impression on a substrate; this type of fossil is an ichnofossil, and in this case an ichnospecies. The U. britannica fish-fin tracks, or trackways are often associated with current or wave ripple marks, probably shallow water, near-shoreline. Other deep water varieties may be less common, or associated with narrowed current flow between obstructions. The sinusoidal high points of the ripple marks may lend itself to the formation of the trackways. See also
External links
2 : Fish trace fossils|Fossil trackways |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。