from the middle Miocene in the La Venta formation, Magdalena River basin, Colombia.

Hoplosternum is normally found in large schools on the muddy bottoms of slow-moving rivers, pools, drainage ditches, and swampy areas.

The walls of the gut are lined with tiny blood vessels into which the oxygen from the air can pass, similar to the function of true lungs.

When there is a severe drought, these air breathers are able to traverse short stretches of land seeking better conditions.

[3] Hoplosternum is a builder of bubblenests from plant parts, some bottom materials, and bubbles formed by a mouth secretion and air.