Part 8

Included Genera.--Type genus only.

Diagnosis.--Differs from the Lari and other Charadriiformes in (1) the low, narrow head; (2) the very large, long pectoral crest; (3) the virtual absence of the incisura capitis or any excavation for M. coracobrachialis cranialis; and (4) the shallow, indistinct tricipital grooves. It agrees with the Procellariiformes and differs from Phaethon and Limnofregata in characters 2 and 4, and in the large, deeply excavated brachial depression. The ectepicondylar spur is better developed than in any of the Pelecaniformes but not as well developed as in the Procellariiformes. The apparently very broad pectoral crest extends much farther distally than in any of the Procellariiformes or even in Limnofregata, to which the fossil is somewhat more similar in this respect. Tytthostonyx differs from any of the taxa compared in having the ventral condyle very rounded, extending distally well past the dorsal condyle.

=Genus Tytthostonyx, new genus=

Type-Species.--Tytthostonyx glauconiticus, new species.

Included Species.--Type species only.

Diagnosis.--As for the family.

Etymology.--Greek, tytthos, little, plus stonyx, any sharp point. The name is masculine in gender and refers to the small, presumably rudimentary, ectepicondylar spur. It should not be confused with the coleopteran genus Tytthonyx, based on onyx, claw.

=Tytthostonyx glauconiticus, new species=

Figures 10, 11

Holotype.--Right humerus lacking the ventral tubercle, portions of the pectoral crest, and other parts of the proximal end, where partially reconstructed, NJSM 11341.

Locality and Horizon.--Main fossiliferous layer of the Inversand Company marl pit, Sewell, Gloucester County, New Jersey; basal portion of the Hornerstown Formation, latest Cretaceous (Maastrichtian); collected 11 October 1973 by David C. Parris.

Measurements of Holotype (in mm).--Length as reconstructed, 110; width and depth of shaft at midpoint 7.0 × 5.6; distal width 14.8; depth through dorsal condyle 8.7.

Etymology.--From Latin, glaucus (Greek, glaukos), bluish green or gray, sea-colored, applied to greensands because of their color, although appropriate because of their marine origins as well; in reference to the holotype having been recovered from beds of glauconite.

Remarks.--A possible relationship between the Procellariiformes and Pelecaniformes has been previously suggested (Sibley and Ahlquist, 1972:70; Olson, 1985:142), and among the pelecaniform taxa most often mentioned as being procellariiform-like are the Fregatidae. It is tempting to regard the humerus of Tytthostonyx as being similar to that possessed by the ancestral stock that gave rise to the Procellariiformes. Its similarities also to the Eocene frigatebird Limnofregata would thus be seen as corroborating the primitiveness of the Fregatidae within the Pelecaniformes. Whereas Tytthostonyx definitely has not achieved the highly distinctive and presumably derived morphology of the humerus of modern Procellariiformes, the incipient development of the ectepicondylar spur and deep brachial depression could be interpreted as tending in that direction.

On the other hand, we must admit that we are dealing with only a single bone and one of very great age at that, so that the risk of overinterpreting the fossil is correspondingly great. We can only discern the overall similarities of the specimen and phylogenetic inferences can therefore be only tentative at best.

=Family and Genus Indeterminate=

Figure 9e,f

Referred Material.--Distal portion of left ulna ANSP 15713.

Locality and Horizon.--Inversand Company marl pit, near Sewell, Gloucester County, New Jersey; Hornerstown Formation, Late Cretaceous (Maastrichtian); not found in situ, collected on shelf formed by “blue bed”; collected 31 August 1977 by Richard S. White.

Measurements (in mm).--Distal width 2.6, distal depth 3.1, width and depth of shaft near point of break 1.8 × 1.9.

Comparisons.--This specimen comes from a very small bird. The only modern pelagic birds in this size range are the storm-petrels of the family Oceanitidae and the fossil resembles this family in the extremely straight shaft of the ulna, the shape and depth of the tendinal grooves, and the relatively well-developed scars for the attachment of the secondaries. It differs from the Oceanitidae in having the ventral lip of the external condyle much more rounded and protrudent past the plane of the shaft, whereas the carpal tubercle in dorsal view is markedly smaller. On this basis, the fossil certainly could not be referred to the Oceanitidae and that it should be associated with the Procellariiformes may be doubted as well.

=Aves, incertae sedis=

Figure 9g

Referred Material.--Distal end of left femur, NJSM 12119.

Locality and Horizon.--Inversand Company marl pit, Sewell, Gloucester County, New Jersey; from processed spoil piles, precise stratum unknown; collected 12 December 1981 by Cynthia Miller. Presumably from the Hornerstown Formation but could be either Late Cretaceous or Paleocene.

Measurements (in mm).--Distal width 4.3, distal depth 3.8.

Comparisons.--This is also from a very small bird, possibly the same size as the species represented by the preceding ulna (ANSP 15713; Figure 9e,f) but probably somewhat larger. It is characterized by an extremely well-developed tubercle for the attachment of M. gastrocnemius lateralis. A perfunctory perusal of modern taxa revealed nothing similar.

=Discussion=