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Complete primate skeleton from the Middle Eocene of Messel in Germany: morphology and paleobiology.

Franzen JL, Gingerich PD, Habersetzer J, Hurum JH, von Koenigswald W, Smith BH - PLoS ONE (2009)

Bottom Line: Darwinius masillae represents the most complete fossil primate ever found, including both skeleton, soft body outline and contents of the digestive tract.Study of all these features allows a fairly complete reconstruction of life history, locomotion, and diet.Any future study of Eocene-Oligocene primates should benefit from information preserved in the Darwinius holotype.

View Article: PubMed Central - PubMed

Affiliation: Forschungsinstitut Senckenberg, Frankfurt, Germany.

ABSTRACT

Background: The best European locality for complete Eocene mammal skeletons is Grube Messel, near Darmstadt, Germany. Although the site was surrounded by a para-tropical rain forest in the Eocene, primates are remarkably rare there, and only eight fragmentary specimens were known until now. Messel has now yielded a full primate skeleton. The specimen has an unusual history: it was privately collected and sold in two parts, with only the lesser part previously known. The second part, which has just come to light, shows the skeleton to be the most complete primate known in the fossil record.

Methodology/principal findings: We describe the morphology and investigate the paleobiology of the skeleton. The specimen is described as Darwinius masillae n.gen. n.sp. belonging to the Cercamoniinae. Because the skeleton is lightly crushed and bones cannot be handled individually, imaging studies are of particular importance. Skull radiography shows a host of teeth developing within the juvenile face. Investigation of growth and proportion suggest that the individual was a weaned and independent-feeding female that died in her first year of life, and might have attained a body weight of 650-900 g had she lived to adulthood. She was an agile, nail-bearing, generalized arboreal quadruped living above the floor of the Messel rain forest.

Conclusions/significance: Darwinius masillae represents the most complete fossil primate ever found, including both skeleton, soft body outline and contents of the digestive tract. Study of all these features allows a fairly complete reconstruction of life history, locomotion, and diet. Any future study of Eocene-Oligocene primates should benefit from information preserved in the Darwinius holotype. Of particular importance to phylogenetic studies, the absence of a toilet claw and a toothcomb demonstrates that Darwinius masillae is not simply a fossil lemur, but part of a larger group of primates, Adapoidea, representative of the early haplorhine diversification.

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Relative size of the eyes and orbits in Darwinius compared to those of other living and fossil primates.Darwinius (D) has orbits in the nocturnal range (solid circles), while Adapis magnus (A1), Adapis parisiensis (A2), and Notharctus osbornianus (N) are in the diurnal range (open squares). Diagram modified from [1: fig. 10] and [55: 7.6].
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pone-0005723-g014: Relative size of the eyes and orbits in Darwinius compared to those of other living and fossil primates.Darwinius (D) has orbits in the nocturnal range (solid circles), while Adapis magnus (A1), Adapis parisiensis (A2), and Notharctus osbornianus (N) are in the diurnal range (open squares). Diagram modified from [1: fig. 10] and [55: 7.6].

Mentions: The overall shape of the Darwinius skull is very similar to the Late Eocene North American cercamoniine Magharita stevensi as reconstructed by Rasmussen in 1990 [37]. The short rostrum, robust lower jaw, and large braincase look almost the same. The relatively larger orbits of Darwinius indicate that the animal could have been nocturnal (Fig. 14). The maxillary suture with the premaxilla and nasal curves in the same way as in M. stevensi, displaying a steep premaxilla/maxilla suture and a caudally gently curving maxilla/nasal suture. In M. stevensi the ratio of the length from the mesial border of the canine to the mesial border of the orbit divided by the length from the mesial border of the canine to the back of the skull is 1/5 [37]. In the Darwinius specimens (plate A and B) the proportions are similar but the flattened specimens are difficult to measure with accuracy. The skull of the European cercamoniine Pronycticebus gaudryi is more robust and has a longer braincase and larger orbits (for systematic discussion see [59]). Contrary to large adapid skulls [28], the zygomatic arch is mesially low and slender, and a crista sagittalis was obviously not developed. A well-developed sagittal crest is also present in Cantius actius (“Hesperolemur” in [59]), but not in M. stevensi or in Europolemur kelleri [19].


Complete primate skeleton from the Middle Eocene of Messel in Germany: morphology and paleobiology.

Franzen JL, Gingerich PD, Habersetzer J, Hurum JH, von Koenigswald W, Smith BH - PLoS ONE (2009)

Relative size of the eyes and orbits in Darwinius compared to those of other living and fossil primates.Darwinius (D) has orbits in the nocturnal range (solid circles), while Adapis magnus (A1), Adapis parisiensis (A2), and Notharctus osbornianus (N) are in the diurnal range (open squares). Diagram modified from [1: fig. 10] and [55: 7.6].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2683573&req=5

pone-0005723-g014: Relative size of the eyes and orbits in Darwinius compared to those of other living and fossil primates.Darwinius (D) has orbits in the nocturnal range (solid circles), while Adapis magnus (A1), Adapis parisiensis (A2), and Notharctus osbornianus (N) are in the diurnal range (open squares). Diagram modified from [1: fig. 10] and [55: 7.6].
Mentions: The overall shape of the Darwinius skull is very similar to the Late Eocene North American cercamoniine Magharita stevensi as reconstructed by Rasmussen in 1990 [37]. The short rostrum, robust lower jaw, and large braincase look almost the same. The relatively larger orbits of Darwinius indicate that the animal could have been nocturnal (Fig. 14). The maxillary suture with the premaxilla and nasal curves in the same way as in M. stevensi, displaying a steep premaxilla/maxilla suture and a caudally gently curving maxilla/nasal suture. In M. stevensi the ratio of the length from the mesial border of the canine to the mesial border of the orbit divided by the length from the mesial border of the canine to the back of the skull is 1/5 [37]. In the Darwinius specimens (plate A and B) the proportions are similar but the flattened specimens are difficult to measure with accuracy. The skull of the European cercamoniine Pronycticebus gaudryi is more robust and has a longer braincase and larger orbits (for systematic discussion see [59]). Contrary to large adapid skulls [28], the zygomatic arch is mesially low and slender, and a crista sagittalis was obviously not developed. A well-developed sagittal crest is also present in Cantius actius (“Hesperolemur” in [59]), but not in M. stevensi or in Europolemur kelleri [19].

Bottom Line: Darwinius masillae represents the most complete fossil primate ever found, including both skeleton, soft body outline and contents of the digestive tract.Study of all these features allows a fairly complete reconstruction of life history, locomotion, and diet.Any future study of Eocene-Oligocene primates should benefit from information preserved in the Darwinius holotype.

View Article: PubMed Central - PubMed

Affiliation: Forschungsinstitut Senckenberg, Frankfurt, Germany.

ABSTRACT

Background: The best European locality for complete Eocene mammal skeletons is Grube Messel, near Darmstadt, Germany. Although the site was surrounded by a para-tropical rain forest in the Eocene, primates are remarkably rare there, and only eight fragmentary specimens were known until now. Messel has now yielded a full primate skeleton. The specimen has an unusual history: it was privately collected and sold in two parts, with only the lesser part previously known. The second part, which has just come to light, shows the skeleton to be the most complete primate known in the fossil record.

Methodology/principal findings: We describe the morphology and investigate the paleobiology of the skeleton. The specimen is described as Darwinius masillae n.gen. n.sp. belonging to the Cercamoniinae. Because the skeleton is lightly crushed and bones cannot be handled individually, imaging studies are of particular importance. Skull radiography shows a host of teeth developing within the juvenile face. Investigation of growth and proportion suggest that the individual was a weaned and independent-feeding female that died in her first year of life, and might have attained a body weight of 650-900 g had she lived to adulthood. She was an agile, nail-bearing, generalized arboreal quadruped living above the floor of the Messel rain forest.

Conclusions/significance: Darwinius masillae represents the most complete fossil primate ever found, including both skeleton, soft body outline and contents of the digestive tract. Study of all these features allows a fairly complete reconstruction of life history, locomotion, and diet. Any future study of Eocene-Oligocene primates should benefit from information preserved in the Darwinius holotype. Of particular importance to phylogenetic studies, the absence of a toilet claw and a toothcomb demonstrates that Darwinius masillae is not simply a fossil lemur, but part of a larger group of primates, Adapoidea, representative of the early haplorhine diversification.

Show MeSH
Related in: MedlinePlus