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Description of a Well Preserved Fetus of the European Eocene Equoid Eurohippus messelensis.

Franzen JL, Aurich C, Habersetzer J - PLoS ONE (2015)

Bottom Line: The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation.Death of mare and fetus were probably not related to problems associated with parturition.Soft tissue interpreted as the uteroplacenta and a broad uterine ligament are preserved due to bacterial activity and allow considerations on the evolutionary development of the structures.

View Article: PubMed Central - PubMed

Affiliation: Department Messelforschung, Senckenberg Forschungsinstitut Frankfurt, Frankfurt am Main, Germany; Department Geowissenschaften, Naturhistorisches Museum Basel, Basel, Switzerland.

ABSTRACT
The early Middle Eocene locality of Grube Messel, near Darmstadt (Germany), is famous for its complete vertebrate skeletons. The degree of preservation of soft tissues, such as body silhouettes, internal organs and gut contents, is frequently remarkable. The present specimen was analyzed for remnants of the reproductive system. Classic anatomy and osteology and high-resolution micro-x-ray were applied to describe the fetus of the European Eocene equoid Eurohippus messelensis. Scanning electronic microscopy (SEM) was used for determination of soft tissue remnants. The fetus is the earliest and best-preserved fossil specimen of its kind. The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation. The apparent intrauterine position of the fetus is normal for the phase of pregnancy. Death of mare and fetus were probably not related to problems associated with parturition. Soft tissue interpreted as the uteroplacenta and a broad uterine ligament are preserved due to bacterial activity and allow considerations on the evolutionary development of the structures.

No MeSH data available.


a) Line drawing of the exposed side of the fetus of Eurohippus messelensis based on a reduced-contrast photo as background. Bones of the mare (black) are shown for orientation. Notice the presence of the uteroplacenta as indicated by a fine wrinkling lateral of the right femur, covering a large part of the fetus. The white line distinguishes the uteroplacenta on the right side from the exposed bones on the left. dP1 = first lower deciduous premolar of the right side, dP4 = last upper deciduous premolar of the right side.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; line drawing: Jens Lorenz Franzen. b) Line drawing of the skeleton of the fetus and adjacent bones of the mare based on a micro-x-ray (Fig 4). The outline of the uteroplacenta is taken from Fig 3a. Dark grey are the bones of the mares, white those of the fetus. Light grey is the uteroplacenta. Lettering is in Fig 3a except for a few bones and the broad ligament, which are only identifiable on the micro-x-ray (Fig 3b). Scale of a and b = 10 cm.–Micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer; line drawing: Jens Lorenz Franzen.
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pone.0137985.g003: a) Line drawing of the exposed side of the fetus of Eurohippus messelensis based on a reduced-contrast photo as background. Bones of the mare (black) are shown for orientation. Notice the presence of the uteroplacenta as indicated by a fine wrinkling lateral of the right femur, covering a large part of the fetus. The white line distinguishes the uteroplacenta on the right side from the exposed bones on the left. dP1 = first lower deciduous premolar of the right side, dP4 = last upper deciduous premolar of the right side.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; line drawing: Jens Lorenz Franzen. b) Line drawing of the skeleton of the fetus and adjacent bones of the mare based on a micro-x-ray (Fig 4). The outline of the uteroplacenta is taken from Fig 3a. Dark grey are the bones of the mares, white those of the fetus. Light grey is the uteroplacenta. Lettering is in Fig 3a except for a few bones and the broad ligament, which are only identifiable on the micro-x-ray (Fig 3b). Scale of a and b = 10 cm.–Micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer; line drawing: Jens Lorenz Franzen.

Mentions: The fetus is preserved as a compact ellipsoid accumulation of bones located cranioventrally to the maternal pelvis (Figs 2–4). From the surface, it is almost impossible to distinguish individual bones with certainty (Fig 3a). The fetal bones are greatly compressed and the joints were not fully ossified. It seems likely that the pelvic area is still covered by remnants of the uteroplacenta. The identification of individual bones thus stems primarily from the micro-x-ray (Fig 4) and is based on size and proportions, special features—such as the third trochanter on the right femur—and on the fact that most of the bones are still articulated at nearly the original positions.


Description of a Well Preserved Fetus of the European Eocene Equoid Eurohippus messelensis.

Franzen JL, Aurich C, Habersetzer J - PLoS ONE (2015)

a) Line drawing of the exposed side of the fetus of Eurohippus messelensis based on a reduced-contrast photo as background. Bones of the mare (black) are shown for orientation. Notice the presence of the uteroplacenta as indicated by a fine wrinkling lateral of the right femur, covering a large part of the fetus. The white line distinguishes the uteroplacenta on the right side from the exposed bones on the left. dP1 = first lower deciduous premolar of the right side, dP4 = last upper deciduous premolar of the right side.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; line drawing: Jens Lorenz Franzen. b) Line drawing of the skeleton of the fetus and adjacent bones of the mare based on a micro-x-ray (Fig 4). The outline of the uteroplacenta is taken from Fig 3a. Dark grey are the bones of the mares, white those of the fetus. Light grey is the uteroplacenta. Lettering is in Fig 3a except for a few bones and the broad ligament, which are only identifiable on the micro-x-ray (Fig 3b). Scale of a and b = 10 cm.–Micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer; line drawing: Jens Lorenz Franzen.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4622040&req=5

pone.0137985.g003: a) Line drawing of the exposed side of the fetus of Eurohippus messelensis based on a reduced-contrast photo as background. Bones of the mare (black) are shown for orientation. Notice the presence of the uteroplacenta as indicated by a fine wrinkling lateral of the right femur, covering a large part of the fetus. The white line distinguishes the uteroplacenta on the right side from the exposed bones on the left. dP1 = first lower deciduous premolar of the right side, dP4 = last upper deciduous premolar of the right side.—Photo: Senckenberg Forschungsinstitut Frankfurt, Sven Tränkner; line drawing: Jens Lorenz Franzen. b) Line drawing of the skeleton of the fetus and adjacent bones of the mare based on a micro-x-ray (Fig 4). The outline of the uteroplacenta is taken from Fig 3a. Dark grey are the bones of the mares, white those of the fetus. Light grey is the uteroplacenta. Lettering is in Fig 3a except for a few bones and the broad ligament, which are only identifiable on the micro-x-ray (Fig 3b). Scale of a and b = 10 cm.–Micro-x-ray: Senckenberg Forschungsinstitut Frankfurt, Jörg Habersetzer; line drawing: Jens Lorenz Franzen.
Mentions: The fetus is preserved as a compact ellipsoid accumulation of bones located cranioventrally to the maternal pelvis (Figs 2–4). From the surface, it is almost impossible to distinguish individual bones with certainty (Fig 3a). The fetal bones are greatly compressed and the joints were not fully ossified. It seems likely that the pelvic area is still covered by remnants of the uteroplacenta. The identification of individual bones thus stems primarily from the micro-x-ray (Fig 4) and is based on size and proportions, special features—such as the third trochanter on the right femur—and on the fact that most of the bones are still articulated at nearly the original positions.

Bottom Line: The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation.Death of mare and fetus were probably not related to problems associated with parturition.Soft tissue interpreted as the uteroplacenta and a broad uterine ligament are preserved due to bacterial activity and allow considerations on the evolutionary development of the structures.

View Article: PubMed Central - PubMed

Affiliation: Department Messelforschung, Senckenberg Forschungsinstitut Frankfurt, Frankfurt am Main, Germany; Department Geowissenschaften, Naturhistorisches Museum Basel, Basel, Switzerland.

ABSTRACT
The early Middle Eocene locality of Grube Messel, near Darmstadt (Germany), is famous for its complete vertebrate skeletons. The degree of preservation of soft tissues, such as body silhouettes, internal organs and gut contents, is frequently remarkable. The present specimen was analyzed for remnants of the reproductive system. Classic anatomy and osteology and high-resolution micro-x-ray were applied to describe the fetus of the European Eocene equoid Eurohippus messelensis. Scanning electronic microscopy (SEM) was used for determination of soft tissue remnants. The fetus is the earliest and best-preserved fossil specimen of its kind. The postcranial fetal skeleton is almost complete and largely articulated, allowing the conclusion that the pregnant mare was in late gestation. The apparent intrauterine position of the fetus is normal for the phase of pregnancy. Death of mare and fetus were probably not related to problems associated with parturition. Soft tissue interpreted as the uteroplacenta and a broad uterine ligament are preserved due to bacterial activity and allow considerations on the evolutionary development of the structures.

No MeSH data available.