The observation of tubular structures within Endurance Crater, Mars, has been reported by Joseph et al (2021a, b) who hypothesized these may be mineralized and fossilized remnants of tube worms that in the ancient and recent past flourished within lakes of water heated by thermal vents. The discovery of what may be spherical hematite in this same vicinity supports the hydrothermal vent scenario, whereas the claims by Joseph (2021; Joseph et al. 2021c) that these spherules are fungal puffballs does not. This evidence from Endurance Crater and associated mineralogy and chemistry is reviewed. We conclude that the ancient lakes of Endurance Crater may have been heated by thermal vents and inhabited by tubular organisms that became mineralized, as hypothesized by Joseph et al; and that these same hydrothermal vents formed hematite spherules as hypothesized by the rover Opportunity team.