Tygobar ProtoNet; Automatic hierarchical classification of proteins More Integrated resource of protein albimaxulatus, domains and functional sites More Additionally, these sequences have been associated with chromosome rearrangements Ruiz-Herrera et al. Sigmodontinae and description of two new species from southeastern Brazil. The mandible lower jaw is long and low. Abstract The recently described taxon Drymoreomys albimaculatus is endemic to the Brazilian Atlantic Forest and its biology and genetics are still poorly known. EMBL nucleotide sequence database More Comments on external morphology and natural history The specimens collected were medium sized male body mass: Telomeric sequences are found near the centromeres of the sex chromosomes. On the sole, the pads are very large.

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It is one of several tribes recognized within the subfamily Sigmodontinae , which encompasses hundreds of species found across South America and into southern North America.

Sigmodontinae is the largest subfamily of the family Cricetidae , other members of which include voles , lemmings , hamsters , and deermice , all mainly from Eurasia and North America. Overall, the fur of the upperparts is orange to reddish- buff.

The sides are reddish brown. On the underparts, the hairs are grayish at the base and white at the tip, except on the throat, chest, and in some specimens groin, where the hairs are entirely white [13] —a trait unique among the oryzomyines. The mystacial vibrissae whiskers on the upper lip are long, usually extending a little beyond the ears when laid back against the head, but the superciliary vibrissae whiskers above the eyes are short and do not extend beyond the ears.

The upper surface on the forefeet is covered with brown fur, and there is white or silvery fur on the digits. Ungual tufts fur around the bases of the claws are present on the second through fourth digits. On the sole, the pads are very large. The nasal and premaxillary bones extend in front of the incisors , forming a rostral tube , which is shared among oryzomyines only with Handleyomys.

The zygomatic notch a notch formed by a projection at the front of the zygomatic plate , a bony plate at the side of the skull is shallow. The interorbital region between the eyes is narrow and long, with the narrowest part towards the front. The crests on the braincase and interorbital region are weakly developed.

The bony palate is broad and short, with the posterior margin between the third molars M3. The coronoid process , the frontmost of the three main processes projections at the back of the jawbone, is large and about as high as the condyloid process behind it. The angular process , below the condyloid, is fairly short and does not extend further backwards than the condyloid.

The upper molar rows are either almost parallel or slightly convergent with each other toward the front. The molars are high-cusped, almost hypsodont. On M1, the anterocone the front cusp is divided into two cuspules on the lingual inner, towards the tongue and labial outer, towards the lips sides of the teeth. The mesoloph , a crest near the middle of the labial side of the tooth, is long and well developed on each of the three upper molars.

On the lower molars m1 to m3 , the cusps on the labial side are located slightly in front of their lingual counterparts. The anteroconid , the front cusp on the m1, is divided in two. The m1, m2, and usually m3 have a mesolophid , a crest corresponding to the mesoloph but located on the lingual side. There are three digits at the tip of the penis, of which the central one is the largest. The two lateral digits are not supported by mounds of the baculum penis bone.

There is only one spine on the papilla nipple-like projection on the upper side of the penis. On the urethral process , located in the crater at the end of the penis, a fleshy process at the side, the lateral lobule , is present.

The preputial glands glands in front of the genitals are large. The lack of lateral bacular mounds, presence of a lateral lobule, and size of the preputial glands are all unique traits among the oryzomyines.

Both sex chromosomes are submetacentric with one arm noticeably longer than the other , and X is larger than Y. Blocks of heterochromatin are present on all autosomes and the long arm of Y. Telomeric sequences are found near the centromeres of the sex chromosomes.

However, no other oryzomyine has exactly the same karyotype as D. This suggests an evolutionary trend of decreasing chromosome number within the clade. While there are some similar cases of relationships between Andean and Atlantic Forest animals, these involve inhabitants of humid forests in the Andes; Eremoryzomys, by contrast, lives in an arid area.

It has been found in disturbed and secondary forests as well as in pristine forest, but probably needs contiguous forest to survive. Reproductive activity has been observed in females in June, November, and December and in males in December, suggesting that the species breeds year-round.


Drymoreomys albimaculatus, o rato da serra









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