Myllokunmingiidae

Myllokunmingiids feature a notochord with vertebral elements, cranial elements, gill arches and filaments, fins with radials, zigzag-shaped muscle segments (myomeres) and paired sense organs on the head. These sense organs include a pair of otic capsules ==Taxonomy==

The validity of the three known taxa is generally accepted. Even so, there has been some debate on whether they are truly distinct. Hou and colleages have argued in 2002 that Haikouicthys is synonymous with Myllokunmingia. Subsequent studies led by the British paleontologist Simon Conway Morris in 2006 and 2012 identified the genera to be distinct on the basis of their gill arrangements, • Family †Myllokunmingiidae Shu, 2003 • Genus †Haikouichthys Luo, Hu & Shu 1999 sensu Shu et al., 2003 • Species †Haikouichthys ercaicunensis Luo, Hu & Shu 1999 sensu Shu et al., 2003 • Genus †Myllokunmingia Shu, Zhang & Han, 1999 • Species †Myllokunmingia fengjiaoa Shu, Zhang & Han, 1999 • Genus †Zhongjianichthys Shu, 2003 • Species †Zhongjianichthys rostratus Shu, 2003 == Paleoecology ==

Myllokunmingiids were likely active swimmers They would have been ideal prey for contemporary predators due to being soft-bodied, muscular and high-calorie targets, driving the evolution of enhanced visual systems (i.e., the four camera-type eyes identified by Lei et al.) that enable detection and evasion of threats. The dense fossil aggregations in which myllokunmingiid specimens often occur may reflect schooling behavior, noted by Lei et al. to be a common anti-predator response in modern teleost fishes. An active swimming lifestyle may explain the rarity of their preservation, which enabled escape from sediment flows that would bury them. In contrast to other myllokunmingiids, Zhongjianichthys likely had a benthic lifestyle with intermittent burrowing due to its inferred limited swimming ability. ==See also==