Weird Early Mammal Birthed Big Babies
Pantolambda bathmodon, a stocky, now-extinct mammal, lived 62 million years ago and reached roughly 92 lbs in adulthood, which was a much larger size than most mammals that came before.
Video credit: G. Funston
Music: "Sheep Rotation" by Jobii
Video credit: G. Funston
Music: "Sheep Rotation" by Jobii
Transcript
00:00 A new study gives a unique window into the life of our ancient cousin, an animal called Pantolambda.
00:05 Paleontologists learned about its growth by making thin sections,
00:10 cutting the bones and teeth thin enough to let light shine through.
00:14 This let Dr. Funston and his colleagues look at growth marks recording the days and years of Pantolambda's life.
00:21 Features of the bone show how fast it grew and how many years old it was when it died.
00:29 The teeth give a more precise record, showing daily pulses of growth during the animal's early life.
00:36 The teeth also record a birth line, showing when the animal was born.
00:42 The team looked further into the life of Pantolambda by analyzing the chemistry of the teeth.
00:48 Using a precise laser to vaporize small amounts of material, they mapped the composition of the teeth.
00:57 This showed chemical changes associated with major events in the animal's life, like birth.
01:03 Using the daily growth marks in the teeth, this allowed them to precisely estimate how long Pantolambda mothers were pregnant,
01:12 and how long the babies suckled before they were independent.
01:16 Based on the birth line in the teeth, the team showed that Pantolambda was pregnant for 7 months, and the baby's teeth developed quickly.
01:25 Babies suckled for about 1-2 months, meaning that they were independent early in life.
01:30 Using marks in the bones, the team found that Pantolambda would have reached sexual maturity in about 1 year.
01:37 And they had a short lifespan, with most individuals dying at about 4 years old, but some individuals living up to 11 years of age.
01:45 This study shows that Pantolambda gave birth to well-developed young, like many living species of hoofed mammals.
01:53 It is the earliest evidence of this type of lifestyle in the fossil record,
01:57 and it gives the clearest picture yet into the lifestyle of a long-extinct mammal.
02:02 Learn more about the study and its importance by checking out the paper, "Out Now in Nature".
02:08 (upbeat music)