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“Missing link” ancestor reported found

May 19, 2009
Courtesy PLoS ONE
and World Science staff

Sci­en­tists say they have found a 47-mil­lion-year-old fossil that is a “miss­ing link” from apes, mon­keys and hu­mans to other mam­mals. Dis­cov­ered in Mes­sel Pit, Ger­ma­ny, the fos­sil, des­ig­nat­ed Dar­win­ius masil­lae, is es­ti­mat­ed to be 20 times old­er than most fos­sils that ex­plain hu­man ev­o­lu­tion.

Dar­win­ius ma­sil­lae, new ge­nus and spe­cies, from Mes­sel in Ger­ma­ny. (Cour­te­sy J. Fran­zen, P. Gin­gerich, J. Ha­ber­set­zer, J. Hu­rum, W. Koe­nigs­wald, et al.)


Known as “I­da,” sci­en­tists said the fos­sil shows char­ac­ter­is­tics from the very prim­i­tive non-hu­man ev­o­lu­tion­ary line of so-called prosimi­an­s—crea­tures such as lemurs—but is more re­lat­ed to the “an­thro­poids,” the group that in­cludes mon­keys, apes and hu­mans. 

At 95 per­cent com­plete, the fos­sil of­fers the most com­plete un­der­stand­ing of any pri­mate so far dis­cov­ered from the Eo­cene era, when mod­ern mam­mals first ap­peared, ac­cord­ing to the in­ves­ti­ga­tors. Their find­ings are pub­lished in the re­search jour­nal Pub­lic Li­brary of Sci­ence One.

For the past two years sci­en­tists led by Jørn Hu­rum of the Uni­ver­s­ity of Os­lo Nat­u­ral His­to­ry Mu­se­um have se­cretly an­a­lyzed the fos­sil. “This is the first link to all hu­mans ... truly a fos­sil that links world her­itage,” said Hu­rum.

The fos­sil was ap­par­ently dis­cov­ered in 1983 by pri­vate col­lec­tors who split and even­tu­ally sold two parts of the ske­l­e­ton sep­a­rately; a less­er part was re­stored and, in the pro­cess, partly fab­ri­cat­ed to make it look more com­plete. Sci­en­tists said this part was even­tu­ally pur­chased for a pri­vate mu­se­um in Wy­o­ming, and then de­scribed by one of the au­thors, who rec­og­nized the fab­rica­t­ion. 

The more com­plete part has just come to light, and it now be­longs to the Nat­u­ral His­to­ry Mu­se­um of the Uni­ver­s­ity of Os­lo in Nor­way. The new pa­per de­scribes the study that re­sulted from fi­nally hav­ing ac­cess to the com­plete fos­sil.

Un­like “Lucy” and oth­er fa­mous pri­mate fos­sils found in Africa’s Cra­dle of Man­kind, Ida is a Eu­ro­pe­an fos­sil, pre­served in Ger­ma­ny’s Mes­sel Pit, the mile-wide crat­er and oil-rich shale is a sig­nif­i­cant site for fos­sils of its time, re­search­ers said. Anal­y­sis in­di­cat­ed that the pre­his­tor­ic pri­mate was a young fe­male. A foot bone called the ta­lus bone links Ida di­rectly to hu­mans, ac­cord­ing to the in­ves­ti­ga­tors.

The fos­sil al­so fea­tures the com­plete soft body out­line as well as the gut con­tents: Ida feasted on fruits, seeds and leaves be­fore she died. X-rays re­veal both ba­by and adult teeth. The sci­en­tists es­ti­mate Ida’s age at death as around nine months, and she meas­ured about three feet (90 cm) long.

Ida is es­ti­mat­ed to have lived 47 mil­lion years ago at a crit­i­cal per­i­od in Earth’s his­to­ry: the Eo­cene, when the blueprints for mod­ern mam­mals were be­ing es­tab­lished. Fol­low­ing the ex­tinc­tion of di­no­saurs, the early hors­es, bats, whales and many oth­er crea­tures in­clud­ing the first pri­mates thrived on a sub­trop­i­cal plan­et. The Earth was just be­gin­ning to take the shape that we know and rec­og­nize to­day – the Him­a­la­yas were be­ing formed and mod­ern flo­ra and fau­na evolved. Land mam­mals, in­clud­ing pri­mates, lived amid vast jun­gle.

Ida was found to lack two key anatom­i­cal fea­tures found in lemurs: a groom­ing claw on the sec­ond dig­it of the foot, and a fused row of teeth in the mid­dle of her low­er jaw known as a tooth­comb. She has nails rath­er than the claw typ­i­cal of non-anthropoid pri­mates such as lemurs, and her teeth are si­m­i­lar to those of mon­keys. Her for­ward fac­ing eyes are like ours – which would have en­abled her fields of vi­sion to over­lap, al­low­ing 3D vi­sion and an abil­ity to judge dis­tance.

The fos­sil’s hands show a hu­manlike op­pos­a­ble thumb, re­search­ers said. Like all pri­mates, Ida has five fin­gers on each hand. Ida would have al­so had flex­i­ble arms, which would have al­lowed her to use both hands for tasks that can­not be done with one – like grab­bing a piece of fruit. Like us, Ida al­so has quite short arms and legs, ac­cord­ing to re­search­ers.

X-rays re­veal a bro­ken wrist may have con­tri­but­ed to Ida’s death – her left wrist was heal­ing from a bad frac­ture, said the sci­en­tists. They be­lieve she suc­cumbed to car­bon di­ox­ide gas while drink­ing from the Mes­sel lake: its still wa­ters were of­ten cov­ered by a blan­ket of the gas due to vol­can­ic forc­es that formed the lake and which were still ac­tive. Ham­pered by her bro­ken wrist, Ida fell un­con­scious and sank to the lake bot­tom, where the un­ique con­di­tions pre­served her for 47 mil­lion years.

The find­ings are to be de­scribed in a doc­u­men­ta­ry, “The Link,” to be screened by the His­to­ry Channel on May 25 at 9pm ET/PT and BBC One in the U.K. May 26 at 9pm BST. It will al­so be broad­cast around the world. An inte­rac­tive web­site about Ida has been launched at http://www.re­vealingthelink.com.

“This lit­tle crea­ture is go­ing to show us our con­nec­tion with all the rest of the mam­mals,” said broad­caster and nat­u­ral­ist Sir Da­vid At­ten­bor­ough. “The link they would have said un­til now is mis­sing ... it is no long­er mis­sing.”


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Scientists say they have found a 47-million-year-old human ancestor that is a “missing link” to the ancestors of apes and monkeys. Discovered in Messel Pit, Germany, the fossil, designated Darwinius masillae, is estimated to be 20 times older than most fossils that explain human evolution. Known as “Ida,” scientists said the fossil shows characteristics from the very primitive non-human evolutionary line of so-called prosimians—creatures such as lemurs—but is more related to the “anthropoids,” the group that includes monkeys, apes and humans. At 95% complete, the fossil offers the most complete understanding of the paleobiology of any primate so far discovered from the Eocene era, when modern mammals first appeared, according to the investigators. Their findings are published in the research journal Public Library of Science One. For the past two years scientists led by Jørn Hurum of the University of Oslo Natural History Museum have secretly analyzed the fossil. “This is the first link to all humans ... truly a fossil that links world heritage,” said Hurum. The fossil was apparently discovered in 1983 by private collectors who split and eventually sold two parts of the skeleton on separate plates: the lesser part was restored and, in the process, partly fabricated to make it look more complete. Scientists said this part was eventually purchased for a private museum in Wyoming, and then described by one of the authors, who recognized the fabrication. The more complete part has just come to light, and it now belongs to the Natural History Museum of the University of Oslo in Norway. The new paper describes the study that resulted from finally having access to the complete fossil specimen. Unlike “Lucy” and other famous primate fossils found in Africa’s Cradle of Mankind, Ida is a European fossil, preserved in Germany’s Messel Pit, the mile-wide crater and oil-rich shale is a significant site for fossils of its time, researchers said. Analysis indicated that the prehistoric primate was a young female. A foot bone called the talus bone links Ida directly to humans, according to the investigators. The fossil also features the complete soft body outline as well as the gut contents: Ida feasted on fruits, seeds and leaves before she died. X-rays reveal both baby and adult teeth, and the lack of a ‘toothcomb’ or a ‘grooming claw’ which is an attribute of lemurs. The scientists estimate Ida’s age when she died to be approximately nine months, and she measured about three feet (90 cm) long. Ida is estimated to have lived 47 million years ago at a critical period in Earth’s history: the Eocene, when the blueprints for modern mammals were being established. Following the extinction of dinosaurs, the early horses, bats, whales and many other creatures including the first primates thrived on a subtropical planet. The Earth was just beginning to take the shape that we know and recognize today – the Himalayas were being formed and modern flora and fauna evolved. Land mammals, including primates, lived amid vast jungle. Ida was found to be lacking two of the key anatomical features found in lemurs: a grooming claw on the second digit of the foot, and a fused row of teeth in the middle of her lower jaw known as a toothcomb. She has nails rather than the claw typical of non-anthropoid primates such as lemurs, and her teeth are similar to those of monkeys. Her forward facing eyes are like ours – which would have enabled her fields of vision to overlap, allowing 3D vision and an ability to judge distance. The fossil’s hands show a humanlike opposable thumb, researchers said. Like all primates, Ida has five fingers on each hand. Ida would have also had flexible arms, which would have allowed her to use both hands for tasks that cannot be done with one – like grabbing a piece of fruit. Like us, Ida also has quite short arms and legs, according to researchers. X-rays reveal a broken wrist may have contributed to Ida’s death – her left wrist was healing from a bad fracture, said the scientists. They believe she succumbed to carbon dioxide gas while drinking from the Messel lake: its still waters were often covered by a blanket of the gas due to volcanic forces that formed the lake and which were still active. Hampered by her broken wrist, Ida fell unconscious and sank to the lake bottom, where the unique conditions preserved her for 47 million years. The findings of the two-year study will be described in a documentary film, “The Link,” to be screened by History on Monday May 25th, 2009 at 9pm ET/PT and BBC One in the UK Tuesday May 26th, 2009 at 9pm BST. It will also be broadcast around the world. An interactive website about Ida has been launched at http://www.revealingthelink.com. “This little creature is going to show us our connection with all the rest of the mammals,” said broadcaster and naturalist Sir David Attenborough. “The link they would have said until now is missing ... it is no longer missing.”