Science Daily

• Scientists were wrong about this strange mammal for nearly 40 years

  A beautifully preserved fossil from Mongolia’s Gobi Desert has solved a mystery that puzzled paleontologists for nearly 40 years. Tamirkhan balcarceli shows that zhelestids were not early relatives of modern placental mammals, despite having teeth that seemed to suggest they were. Instead, the rabbit-like animal belonged to a separate lineage of small Cretaceous mammals.

• Scientists may have misread a 2-billion-year-old clue about Earth

  Scientists have found that a famous 2-billion-year-old chemical signature, once thought to record a massive global change in Earth’s carbon cycle, may instead have been produced by local magma, hydrocarbons, and methane-eating microbes. The discovery raises new questions about what was really happening as oxygen transformed the young planet.

• 160-million-year-old proteins show surprising power against superbugs

  Scientists resurrected antimicrobial peptides from mammals that lived millions of years ago and found that some were more potent against drug-resistant bacteria than modern human versions. These evolutionary relics could provide new clues for designing treatments as antibiotic resistance becomes an increasingly serious threat.

• 1.7-billion-year-old fossils reveal a crucial clue to the rise of complex life

  Scientists studying ancient Australian rocks uncovered more than 12,000 fossils from some of the oldest known eukaryotes on Earth. These early complex cells lived in settings ranging from coastal mudflats to the open sea, but only where oxygen was available. Oxygen-free environments contained simpler microbes instead. The findings strengthen the idea that oxygen played a crucial role in the emergence of complex life.

• These medieval graves looked like family burials. DNA told a different story

  Ancient DNA shows that adults and children buried together in medieval Sweden were often not members of the same immediate family, suggesting that burial choices reflected more than biological kinship. The research also revealed early gender-based burial customs and uncovered the remarkable story of a young woman who may have completed a pilgrimage across Europe.