Level 1 — Absolute Beginner
A long time ago, human relatives walked on Earth with us.
One kind was called Paranthropus boisei. Scientists only had its skull and jaw before.
Now scientists found footprints in Kenya. The footprints are 1.4 million years old.
The footprints show these human relatives were big and walked together in groups.
- footprint
- a mark left on the ground by a foot
- ancient
- very old, from a long time ago
- skull
- the bones that form the head
- jaw
- the bones that hold the teeth and open the mouth
- scientist
- a person who studies the natural world to learn new facts
- species
- a group of living things that share the same features
- group
- a number of people or things together
- relative
- someone related to another, sharing an ancestor
Level 2 — Elementary
Scientists have discovered a 1.4 million year old trail of footprints near Lake Turkana in Kenya, made by an extinct human relative called Paranthropus boisei.
Until now, most of what scientists knew about this species came from fossil skulls and heavy jawbones, which gave few clues about its body size or behavior.
The newly studied footprints include 21 tracks made by eight individuals walking together along an ancient lakeshore.
Researchers believe most of the trackmakers were large adult males, and the biggest footprints suggest individuals stood almost six feet tall, much larger than earlier estimates.
- trail
- a series of marks or signs left by something moving
- extinct
- no longer existing; died out completely
- fossil
- the preserved remains or traces of an ancient living thing
- lakeshore
- the land along the edge of a lake
- trackmaker
- the animal or person whose footprints created a trail
- estimate
- an approximate calculation or judgment of an amount
- researcher
- a person who studies a subject carefully to discover new facts
- individual
- a single person or living thing, considered separately
Level 3 — Intermediate
An international team of researchers has described a 1.4 million year old trackway near Lake Turkana in Kenya, attributed to Paranthropus boisei, a robust hominin that coexisted with early members of our own genus before disappearing without leaving descendants.
Because the fossil record for the species has consisted almost entirely of skulls and massive jawbones adapted for heavy chewing, scientists previously had little direct physical evidence for estimating its stature or posture below the neck.
The trackway, first discovered at the site nearly fifty years ago and only recently analyzed in full, preserves 21 tracks attributed to eight individuals moving together, with anatomical features suggesting the group was composed mostly of large adult males.
The largest footprints indicate individuals stood as tall as 1.8 meters and weighed around 75 kilograms, findings published in the Proceedings of the National Academy of Sciences that substantially revise earlier, more modest estimates of the species' body size.
- trackway
- a path of preserved footprints left by animals moving together
- hominin
- a member of the group including humans and their close extinct relatives
- coexist
- to exist together at the same time or in the same place
- genus
- a scientific grouping of closely related species
- robust
- strongly built and physically powerful
- posture
- the position in which a body is held while standing or moving
- anatomical
- relating to the structure of the body
- revise
- to change or update based on new information
Level 4 — Advanced
An international research team has characterized a 1.4 million year old trackway near Lake Turkana in Kenya, attributing it to Paranthropus boisei, a robust hominin that coexisted with early representatives of our own genus before vanishing from the fossil record without leaving any surviving descendants.
Because the fossil record for this species has consisted almost exclusively of crania and massive jawbones adapted for forceful mastication, researchers previously possessed scant direct evidence from which to infer its stature or postural characteristics below the neck.
The trackway, initially uncovered at the site nearly five decades ago yet only comprehensively analyzed in recent years, preserves twenty-one discrete tracks attributed to eight individuals moving in concert, with anatomical indicators suggesting the cohort was composed predominantly of large adult males.
The most substantial footprints indicate individuals stood as tall as 1.8 meters and weighed approximately 75 kilograms, a finding published in the Proceedings of the National Academy of Sciences that substantially revises earlier, considerably more modest estimates of the species' physical stature.
- characterize
- to describe the distinctive features of something
- cranium
- the skull, particularly the part enclosing the brain
- mastication
- the act of chewing food
- scant
- very small or barely sufficient in amount
- infer
- to reach a conclusion based on evidence and reasoning
- discrete
- individually separate and distinct
- cohort
- a group of individuals sharing a common characteristic
- predominantly
- mostly; for the greater part
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