Ornithichnites, or foot-marks of several extinct species of birds, found in the New Red sandstone of the Valley of the Connecticut.* (Hitchcock.) [040]

The fossil tracks on this Plate are all nearly on the same scale: viz. one-twenty-fourth. The recent footsteps are on a larger scale. [041]

Fig.  l. Ornithichmtes giganteus. Many tracks of this species occur at Mount Tom, near Northampton, U. S.

Fig. 2. O. tuberosus. Portions of three tracks, and a single footstep of a fourth appear on the same slab. The two longest of them are in opposite directions.

Fig. 3. O. tuberosus, on a slab in front of the Court House in Northampton, from Mount Tom.

Fig. 4. O. ingens, from a quarry called the Horse Race, near Gill. The appendage to the heel is not distinct in this track.

Fig. 5. O. diversus, on a flag-stone near the first church door at Northampton, U. S.

Fig. 6. O. diversus. We have here three rows of tracks and a single footstep, from the Horse Race Quarry. These tracks shew no marks of any appendage to the heel.

Fig. 7. O. diversus; found near South Hadley, U. S.

Fig. 8. O. diversus; curvilinear track from the Horse Race Quarry.

Fig. 9. O. diversus. Two parallel tracks from the Horse Race Quarry.

Fig. 10. O. diversus; nearly parallel tracks of two birds, with an appendage behind each foot; from the quarries at Montague, U. S.

Fig. 11. O. minimus; common at the Horse Race Quarry; similar impressions of the feet of small birds vary from half an inch to an inch and half in length.

Figs. 12. 13. 14. O. diversus; from the Horse Race Quarry. Tracks of diflerent individuals of different species, and different sizes cross one another confusedly in these three slabs.

Fig. 15. Recent track of probably a Snipe. [042]

Fig. 16. Recent track of a Pea-hen.

Fig. 17. Recent track of a domestic hen.

* In the American Journal of Science and Arts, January, 1836. V. XXIX. No. 2. Professor Hitchcock has published a most interesting account of his recent discovery of Ornithicknites, or foot-marks of birds in the New Red sandstone of the valley of the Connecticut. These tracks have been found at various depths beneath the actual surface, in quarries of laminated flag stones, at five places near the banks of this river, within a distance of thirty miles. The sandstone is inclined from 5°, to 30°, and the Tracks appear to have been made on it before the strata received their inclination. Seven of these tracks occur in three or four quarries within the space of a few rods square; they are so distinct, that he considers them to have been made by as many different species, if not genera, of birds. (See Pl. 26a, Figs. 1-14.)

The footsteps appear in regular succession, on the continuous track of an animal in the act of walking or running, with the right and left foot always in their relative places.

The distance of the intervals between each footstep on the same track is occasionally varied, but to no greater amount than may be explained by the Bird having altered its pace. Many tracks of different individuals and different species are often found crossing one another; they are sometimes crowded like impressions of feet on the muddy shores of a stream, or pond, where Ducks and Geese resort. (See Pl. 26^a. Figs. 12. 13. 14.)

None of the footsteps appear to be those of Web-footed Birds; they most nearly resemble those of Grallæ, (Waders) or birds whose habits resemble those of Grallæ. The impressions of three toes are usually distinct, except in a few instances; that of the fourth or hind toe is mostly wanting, as in the footsteps of modern Grallæ.

The most remarkable among these footsteps, are those of a gigantic bird, twice the size of an Ostrich, whose foot measured fifteen inches in length, exclusive of the largest claw, which measured two inches. All the three toes were broad and thick. (Pl. 26^a. Fig. 1. and Pl. 26^b. Fig. 1.) These largest footsteps have as yet been found in one quarry only, at Mount Tom near Northampton; here, four nearly parallel tracks of this kind were discovered, and in one of them six footsteps appeared in regular succession, at the distance of [040]  four feet from one another. In others the distance varied from four to six feet; the latter was probably the longest step of this gigantic bird while running.

Next in size to these are the footsteps of another enormous bird (Pl. 26^a. Fig. 4.) having three toes of a more slender character, measuring from fifteen to sixteen inches long, exclusive of a remarkable appendage extending backwards from the heel eight or nine inches, and apparently intended, like a snow shoe, to sustain the weight of a heavy animal walking on a soft bottom. (See Pl.26^b. Fig.2.) The impressions of this appendage resemble those of wiry feathers, or coarse bristles, which seem to have sunk into the mud and sand nearly an inch deep; the toes had sunk much deeper, and round their impressions the mud was raised into a ridge several inches high, like that around the track of an Elephant in Clay. The length of the step of this Bird appears to have been sometimes six feet. On the other tracks the steps are shorter, and the smallest impression indicates a foot but one inch long, with a step of from three to five inches. (Pl. 26^a. 2. 3. 5—I4.)

In every track the length of the step increases with the size of the foot, and is much longer in proportion than the steps of any existing species of birds; hence it is inferred that these ancient birds had a greater length of leg than even modern Grallæ. The steps at four feet asunder probably indicate a leg of six feet long.

In the African Ostrich, which weighs l00 lbs, and is nine feet high, the length of the leg is about four feet, and that of the foot ten inches.

All these tracks appear to have been made on the Margin of shallow water that was subject to changes of level, and in which sediments of sand and mud were alternately deposited, and the length of leg, which must be inferred from the distance of the footsteps from each other, was well adapted for wading in such situations. No Traces of any Bones but those of fishes (Palæothrissum) have yet been found in the rock containing these footsteps, which are of the highest interest to the Palæontologist, as they establish the new fact of the existence of Birds at the early epoch of the New Red sand stone formation; and further shew that some of the most ancient forms of this class attained a size, far exceeding that of the largest among the feathered inhabitants of the present world, and were adapted for wading and running, rather than for flight.